Ooh!! You might get a new horsie! There was a lady at our barn several years ago who bought this hideously shaggy and scrawny TB looking thing she found in a pasture. He had great bone structure though and was a beautiful mover. After some major TLC and training he competed for years in the A/O's at huge AA shows. He won absolutely EVERYTHING! He was so ridiculously fancy once he filled out. Make sure that his bone structure won't affect his future soundness (esp as a hunter he'll need to stay sound over fences) or his movement (in the hunters movement is everything). I agree that $2500 is pretty steep for an OTTB that's only 5 weeks off track. Can you bring them down a bit? I'd use that extra money to get a solid vet check, xrays if you can afford it.
JDI -- I think that $2500 is way too much for a horse off the track. Many you can get for free, a zillion you can get for less than $1000. Basically, if they don't move the horse out, it ends up for slaughter. A non-racing horse just costs the owner money and they generally want them OUT!
However, in the end it's your choice obviously. People have had their dream horse for free, or thousands of dollars. You need to ask is this horse worth $2500 TO YOU. Do your homework for injuries, attitude, training you expect, and so on, in regard to where you want to go with him.
Sometimes, there is no amount of money in the world that is too much for just that pet!