I have done a few of these conversions. There is substantial work involved. But it would be a great learning experience for someone just getting involved. And if it turned out to be a not so great job, well it's a Thompson Center, not out a bunch, and it can always be fixed.
As for values of TC's, I have been surprised how much folks are asking, and sometimes getting for them at gun shows and such places.
Often $400 and more.