Most teflon refinishing techniques I've checked go for a little over $200. Certainly will eat into any profit you were hoping to make. (But any total refinishing is not going to be what I'd consider significantly cheaper....especially if you have someone else strip it down to the metal parts for you.)

Good luck!

P.S. Parkerizing would be least expensive, maybe $100. to 130. or so! Blueing would split the difference!