I think he is a nice looking horse but with his pasterns, I would say he is going to have to struggle to really get that slow, soft, engaged jog. As a 3 year old, he may finish out but I doubt his pasterns are going to change much. They aren't straight upright, but they are up enough to make things a little bumpy. If you are looking to do open shows and such with him, I think with the right training he could be competitive. But if you are thinking more along the lines of bigger shows and such, I don't think he would fair well. $2500 is a pretty good price but considering you are going to need a couple months training...that really takes him up to about $4K. You can give him the training but you can't fix the conformation. His resale value will be affected by his faults.
Overall, he is a nice looking horse, very pretty face and looks to be pretty well balanced head to tail. The market is so soft right now, I think you could find something similarly priced with a little better confo.