I would agree that a fastback at 3000 would be worth it. Dam even though I got my car for 3,800 with a new rebuilt engine, leather seats in good condition and very small amount of rust, it sadly has a salvaged title. BUT I LOVE MY CAR
Buy the car that you want. I bought a 68 coupe from a friend of my brothers, did some work on it until I found a 69 Mach 1. Both cars needed MAJOR restoration and I (stupidly) jumped the gun on both. I guess the lesson is: Take your time, find the car you want in the condition you want. It's hard to work on frame restoration and structural integrity when all you can think about is cruising and performance mods.