Whats the average cost to restore a 69-71 Cuda or GTO?

I am looking around to find a 69-71 Cuda, GTO, or possibly Duster. I'm attempting to find one in the 2-3k range with minimal rust. I'm no where near a mechanic but would like to find a project car for my dad and I to work on as a way to hang out and spend time together. What are the average costs to fully restore these cars. (426 or 440 engine, 455 on GTO).