iPhone 5 or Wait?

I would bet that a new iPhone comes out this fall. So there's that, or the 5's will be discounted

 

If Apple follows their previous history, the 5s will be released around the same time as Mavericks. Unless you need a new phone now due to hardware problems etc. I would wait.

 

Apple is been on a yearly schedule, so I'd be very surprised if they skip this year.

Replace the battery yourself. Ifixit sells a complete kit I believe.

 

if you wanna save some money and buy a brand new iphone 5 off ebay, now it's time since the expected 5s might not be a big upgrade based on the experience from previous years. however, if you are going to buy one from apple directly, the price is still the same as when the iphone 5 firstly came out, maybe just wait.