Welcome aboard Von
That is a loaded question, there are many factors that determine a cars value (and location is a big one)
My advise to you would be to go through the "cars for sale" section of our forum and see what others are asking for the car you like, and what they are getting for it
Then, make yourself a score sheet
For instance, a 67-72 is worth 20 points, but a 73 and up is 10
A slant six is 5 points, a 318 10, a 340 or 360 15 points and a big block 20
Go through the options, transmission, paint, you name it and that way you can compare cars and see which on you like best, and budget accordingly
(Keep in mind rust might knock 45 points off of a otherwise perfect car)