I once bought a totalled car that had zero mechanical damage intending to repair it and resell it. ( The car had rolled over so it looked like Godzilla chewed it, but the motor ran and everything else worked perfectly, but the radiator)
After a couple of months working on it, it became clear that I was going to need to invest more in time and parts than the ammount I intended to get out of it, so I sold it and the remaining replacement parts as it was to a guy that did that for a living, losing money in the process.
It might be a good idea if it was a classic car you are rebuilding for your own use and enjoyment, otherwise i recommend you really really think it out.
After a couple of months working on it, it became clear that I was going to need to invest more in time and parts than the ammount I intended to get out of it, so I sold it and the remaining replacement parts as it was to a guy that did that for a living, losing money in the process.
It might be a good idea if it was a classic car you are rebuilding for your own use and enjoyment, otherwise i recommend you really really think it out.