"71 cuda/727 has everything is with the car except replacement panels."
Has everything and everything in usable condition are two completely different things. Door panels, seat covers, seat foam, carpet, headliner, dash pad, package tray, glass, weather strip pieces, A and B pillar trim, instruments, and rear view mirror can put you 6 K in the hole before you start. To make the engine bay presentable your looking at another 2K just in hard parts (no paint) that almost always need replacing. Then the engine and the trans need to be gone thru. Brakes, brake lines, pads and shoes and on and on and on. If I was to take this on for a customer (which I don't do any more) it would be 35-40K depending on what extras are found. And that is using Sherman panels. Want better panels and you can tack on another 2K to "upgrade". As others have said, if you do the work yourself then I would go for it; if hiring out, I guess I would pass and get one that is already done. Just curious, what engine is in there, looks like it had a hard life.