I've got an 1800mah 2s SkyLipo with a lot of life left in it... I had bought it for my mini revo, but I have since bought the 2500mah spec packs instead.
Heck... I totally forgot about the 1650mah 3s skylipo I have too... not the best shape, but it isn't puffed, and it balances well still... $20 for both the 2s and 3s