Do you have a Target? They have 15 ft. pools on sale for $159. Somebody gave us one (we were too chicken to buy one, for fear it would be a waste). But we have been SO happy with it. They used it for three years, and just packed it up nicely each fall.
It took DH and I less than one hour to set it up, not knowing what we were doing! Very low maintenance. Ours came with a cover and pump. The extras you might want are a skimmer net ($10), floating chlorine dispenser ($10), and a chemical starter kit ($17), which should last awhile.
I think these pools were $279 a few weeks ago.
Anyway, we are thrilled. All the cousins and friends have been coming over, so my kids are a lot less lonely (we live in the country).
Feel free to PM me if you have any questions!
Good luck !