I don't know about Camry conversions but to do an auto to manual conversion on a 2000 Honda Accord would run $1,500 to $2,000, labor included. I would assume that a Camry would be similar in price.
This swap is somewhat common on Accords since the automatic transmission on both I4 and V6 Accords from 1998 to either 2000 or 2001 were notoriously bad (besides my Camry I have a '99 Honda Accord, 5-speed manual).
edit: Here's a link to a "how-to" thread for doing the swap in Honda Accords:
http://www.honda-tech.com/zerothread?id=1237137
it might give you some ideas. You can always post a question at that forum too if nobody here has done it since the Camry's automatic transmission is a decent transmission (unlike that generation of Accord).