I tried to post this as a deal with the 10% off EBAY coupon for Valentines Day but it doesn't meet deal requirements.
I'll put it here as I think it is worth mentioning.
LOWRANCE ELITE-4 CHIRP WITH NAVIONICS GOLD CARD MAP
http://www.ebay.com.au/itm/222008185998
For $399 less 10% you get a CHIRP sounder with GPS and Gold Navionics maps.
Navionics discontinued Gold maps on 1/1/16 and this sounder has now been replaced by the Hook 4.
Nevertheless for this sort of price, this is a great deal, particularly when you consider the maps are worth at least $100 alone.
Sure there are better sounder/plotters out there, but at this price, I am not so sure.