Be very, very, very, very cautious.
Some states are quite rigorous in inspecting rebuilds prior to retitling them, some not quite so much, some not at all.
As for price, around 50% of normal or less, unless it's a very rare and desirable vehicle. Watched a rebuilt titled 40th Anniversary Mustang GT convert, was a gorgeous car, sell for $2400 last month at an auction. It was loaded, looked quite good, and whatever repairs were done appeared to be done well when I crawled over and under it.