Could be had for very little, relative to his stats, assuming Denver is going with TT. Why not bring him in to compete? If nothing else, he'd be an elite 2nd QB behind Fitz. He's not a glamour name at QB, certainly not mentioned with the Brady's and Manning's. But, his stats the last 2 seasons:
2010/2009
TD's : 20/21
INT: 9/12
Yds: 3653/3802
Note: Only 13 games in 2010 because of Tebow taking over. Would've likely ended up with 4200+yds and 23Td's. His QB rating is a hair under 90.