Don't worry, it'll be ok in the end, a year from now when you have spent a little bit and have a nice coupe, you'll be glad you got it and the money spent won't matter so much, hopefully.
At least after owning one, you'll know a hell of a lot more about the cars (I know I will) like how they should ride and handle, what to look for mechanically and body-wise, what to "feel" for when driving it and a load of other stuff, that can help seperate the good from the bad.
If you get another in the future, you'll be able to pick up on a lot of things very quickly (obviously not an impending belt failure but we're not all mechanics!) but there is always an element of gambling on any old second-hand motor, no matter how much homework you have done.