If you plan on driving the car for the next couple years, then fixing it would be an ok option, but know that you’ll have a lot of headache getting it inspected to show it is back up to safety standards so you can actually get the salvage title. You’ll also have a drastically lower resale value, as noted before.
if you want to do this to flip the car and make money, good luck. Unless you do all the work yourself, find parts cheap, and have a body man who will work for peanuts, you are not going to come out ahead. The best and easiest solution would have been to grab the other shell, swap everything into that, and use that shell for parts. If you had a sentimental attachment to the car, then you coul always fix it later and swap everything back in when done.
Good luck either way, and let us know how it turns out.