How much did it cost you?

This. Had I not gotten my Swinger for dang near free, this is what I would have done. I'm doing mine myself as I do have a little experience and training in paint and prep and welding but I'm still probably looking at 10 grand at least in getting the car set to where i want it.

I bought the car for $565 (Really pissed off the guy on ebay who bid $560 lol) so at least I didn't have much in the price of the car, and it was a roller with a MINT back seat and door panels. So I think it was worth it in the end.

I paid $17k for my Dart. The paint is decent driver quality. The interior is nice. It had been converted to a big block, subframe connected, Dana 60 with Detroit locker, full Calvert rear. It was a Procharged 440. He did a piss poor engine build, unfortunately, and it didn't last. I'll have another $15-16k in this new engine build by the time it's completed. All for a car I'd probably be lucky to get $18k for if I ever wanted/needed to sell it.

Do it because you love it, or because it's your passion. It's almost never worth the money/time you put into it.

I don't know if you've looked recently, but a fully built, rotisserie-quality build on a '73 Swinger like mine will fetch ~$14-$15k, max.

I'm definitely upside down on the car, but I had an absolute blast building it, and it's an awesome car to drive. If we weren't throwing money in these cars, we'd be pissing it away somewhere else.