I've made over 400 purchases from aliexpress over the last few years and thought I'd share some methods I've picked up.
Aliexpress is similar to amazon in that it is a "shopping centre" which allows sellers to have a platform for selling their goods. Sellers are mostly from China but can be from anywhere in the world (there are Australian sellers on Aliexpress).
Aliexpress can be an excellent source of goods and products as well as finding manufacturers for particular items (a few months ago I was looking at importing a container of tractor tyres). Goods can be bought individually or in-bulk. - do you need 1000 microsd card adapters? With low manufacturing costs it is undeniable that China produces a lot of goods. Also China has a population of over 1 Billion people so it is a "global economy" within it's own borders. A huge internal market place that can support it's own industry. unlike "little" Australia in so many industries.
Finding the lowest price the method to obtain best results on aliexpress is to search for the item you want. Open up a few tabs with the desired item and then scroll down the page to "From Other Sellers" and scroll through those. find the few cheapest price there and then search again in those products in "From Other Sellers" for an even cheaper product.
Aliexpress search and "sort by price low to high" doesn't always show the lowest (rarely)
find the cheapest but make sure the seller has good feedback. obviously sometimes new sellers offer a low price and they could be legit and starting out so it may be worth the risk. alipay buyer protection is pretty good. Also check below about coupons.
Aliexpress use to have (up until about 6 months ago) "search by number of items" and "search by price per piece". these were great. if you wanted 10 of something then you could search for number of items between 9 - 11 and then sort by price per piece to find the best price (as well as searching "from other sellers".
using the aliexpress mobile site m.aliexpress.com this is the mobile site. sometimes prices are cheaper on this site than the www site. both work together in terms of you can have your shopping cart loaded and the same will show up on each site and then you can compare prices to see if the m.site is cheaper.
vouchers/coupons there seems to be 2 types of coupons available. Aliexpress or Seller vouchers. Sometimes aliexpress has special deals to entice new users such as this $5 off a $20+ order for new users. Sometimes sellers have their own specials/couponswhich you have to look at the actual product page to see (if there is one there) such as this seller who offers $1 off for every $7. again you need to compare and look at other items & sellers. So if you're looking for a particular item then open multiple windows of that item from different sellers and look for any that may offer a coupon.
bulk discounts some stores offer offer bulk discounts. small bulk - I recently bought some XXXXX. 1 was $5 delivered, with 2 the price went to $4.85 each, 3 - $4.60, 4 - $4.45. at 5 the price stayed at $4:45 but then shipping kicked in (size of package). I need 10 so I made 3 seperate orders to maximise the discount.
large bulk - if you're buying, say, 100 of something -e.g. micro usb cables (not 100 paper clips) then look for the bulk sellers. again, there used to be a quantity search facility but that has long gone. :( There is also alibaba which is more of a wholesale/bulk marketplace where you can source larger quantities.
finding items i've bought some PCBs from aliexpress - e.g. LCD video driver board. sometimes the PCB board number is enough to yield results. however (especially for OS models) it is necessary to do a bit of googling. This may involves searching using the TV model, which may yield alternative model numbers for the same device. PCBs may be listed under the alternative boards. Also searching suppliers (e.g. PCB board/spare parts shops on line) to find the board which may have an alternate model/part number - then search on aliexpress using that. sometimes checking out forums provides leads for alternate parts that can fit.
payment on aliexpress - I've seen many comments on ozbargain stating something like "i won't use aliexpress because they don't use paypal and I don't trust this chinese site". Aliexpress has its own eschrow service -alipay. Aliexpress and Alipay are part of the Alibaba group. this consortium is huge. Alibaba is larger than amazon. This is not some third rate site. It's a behemoth. Always use a foreign transaction friendly card like 28degrees, citibank or bankwest silver(?) - which attract no foreign conversion fees. I've been using the same card all these years and have never had a problem with CC security.
aliexpress disputes when received sometimes the item isn't at all what was advertised, or arrives broken or unfit for use, or you haven't received it. and you're not happy. fair enough. Just like ebay/paypal there is a dispute resolution service. this can be found on your order page.next to the item - "open dispute". Always provide a screen shot or detailed photo of the issue. or for non-receipt , simply state item hasn't been received. Out of all of my 400+ orders I have probably raised 8 disputes - 4 were fake microsd cards(yeah, it took me a while), 3 for non-reciept of goods and 1 for broken item. In all cases I received my money back.
clothing Generally chinese sizing is smaller. always read the sizing charts in the description very carefully. I once bought some XXL shorts (I'm L in Aus) thinking they should be ok. but they were still too small. re-reading the sizing chart I realised my own stupidity for not reading it correctly. Also check feedback and see what other people have stated about sizes. I generally don't buy too much adult clothing on aliexpress. but kids stuff can be good and inexpensive. especially as kids grow out of and/or ruin their clothing pretty quickly.
things to not buy on aliexpress There are probably many things not to buy from aliexpress for various reasons e.g. pirated goods, fake goods, just plain crap quality, etc. amongst the things I would never buy are memory cards, ram and storage. All of these can be obtained from ebay or locally (via a deal) or from a reputable online service (e.g. Amazon, mymemory, etc) - this is certainly not to say that fakes don't pop up on those sites - especially ebay. My own experience has been "if it looks to good then it probably is fake" - especially with microsd cards. just don't waste your time (i have always had my money refunded via alipay after providing screen dumps of H2Testw results). Mobile phones are also often misrepresented - always check the seller feedback (have they sold a lot of them and had feedback that reflects quality? or have they only sold knitting needles and have just selling mobile phones —- hmmmm, avoid, or is every 10th feedback neutral or negative? sometimes it pays to check out the negative feedback of the seller. many buyers, for example, will buy a super cheap MicroSD and then put it in there phone which will recognise it as e.g. 128gb, and then they will post a review stating "item as described, excellent" or similar. however some people will test the card with H2Testw to find it's true specs. they (the informed) will then post negative or neutral feedback with solid evidence of poor quality or fake goods - or if legit then they will state that H2Testw had varified the validity of the item (all good! - but still do your own checks)
super deals everyday at 5pm aliexpress lists about 70 "super deals". these are meant to be great deals. sometimes a particular item is the cheapest, however more often than not there are cheaper alternatives. - again search "from other sellers".
flash deals found on the mobile site. they go for an hour, every hour. usually about 8 items. Again, not always the cheapest but sometimes they are the cheapest. - again search "from other sellers".
is aliexpress the cheapest? Mostly but not always. When using aliexpress, like with any site, it pays to compare alternate sources/suppliers. recently I bought a samsung TV replacement remote control. I thought I did well finding it for US$3.11 delivered. - received the remote and it worked perfectly with my Gen4 32" TV. I was looking at everbuying and they had the same remote for US$2.65 (using discount code, mobile site and EB point redemption). sure only US$0.46 cheaper but this is Ozbargain. And as said above - memory cards, ram and HDD/SSD storage can usually be found cheaper on ebay (during a sale) or other supplier.
stuff that I regularly buy on Aliexpress - there are 4 people with long hair in my house. so hair ties are always in demand. i usually buy a pack of 100 for US$3.50 every 6 months. the kids delight in losing them. Stuff that I sell on ebay - I make nice pocket money buying stuff cheap on aliexpress in bulk and then flogging it for 200% profit on ebay or gumtree. It's about finding the right product, sourcing it cheaply and knowing what the best price you can get for it. For a while I did OTG cables. I'd get them for US$0.19cents each on aliexpress and then sell them on ebay for $9. after postage and fees I ended up with $7.50 profit. I'd sell 20 or so a month. it would take me 5 minutes to pack one (standard envelop and stamp) and walk to the post box. beer money.
Anywho, that's just some thoughts and tips based on my experience with Aliexpress.
Like every site, there are customers/users who have had negative experiences, I have had nothing but success with Aliexpress
Other people will have other methods for maximising the aliexpress experience, as well as tips for avoiding traps/mistakes.
feel free to leave any further advice/suggestions.
sorry for the long read. cheers