You will recoup at least half the cost if not a little more. Six speeds always sell for more.Too much money even if you are willing to do it yourself, and you'll never recoup that investment. I owned a beautiful low mile 97 TT auto which I ended up selling to buy a 6 spd. Best damn decision I made. Now I've got the right platform for my build.
Good luck whichever route you choose to go.