Used to be around the $100 mark, currently selling for $64 from Catch (https://www.catch.com.au/product/foscam-c1-lite-ip-security-...) or $58 from Mwave (https://www.mwave.com.au/product/foscam-c1-lite-10mp-wireles...), this is the cheapest I've seen these being sold for.
Note that this is the "Lite" version, so no night vision (ie no IR lights on it) but they do operate to quite low lux levels. They are also fixed ie not pan/tilt/zoom. It is also only 720p but the quality of the images from this little camera (when there's enough light) is impressive. Last year a neighbour who had recently bought some expensive security cameras saw the images from mine and was seriously pissed (they ended up returning theirs).
I personally have four of the things. Three of them are mounted outside, albeit in covered areas so protected from weather, and the other is inside the laundry and pointed at the back door. Yes, you can get cameras from the likes of Xiaomi for half the price, but this entry level Foscam basically comes with the lot - built in microphone & speaker, sets clock via ntp, save video and snapshots to ftp servers, motion detection, push alerts - and you don't need to go through Chinese cloud services or flash them with specific firmware and worry about firmware updates borking them. You can use their free web service to view video remotely, and optionally pay for the service to store video, or you can run them 'offline' without an issue. As a bonus, Foscam is widely supported by many third party systems - I was using mine linked into my Vera home automation server and have recently shifted over to Home Assistant. Have been using them for a couple of years now without an issue.
I'm tempted but personally won't be buying any more - if/when my cameras outside start to die due to bugs/spiders I'll probably replace them with the higher end Foscam cameras that are designed to be mounted outside - but if you're looking for something (relatively) cheap/cheerful then these are definitely worth considering.