I would take Knight if it brought us Bledsoe. He is only 25, and if people are saying that Jrue, AD, and Boogie still haven't reached their prime, then certainly Knight has plenty of room to grow (as he is younger). He can also score, so if you put him on your bench you wont go dry.
At this point, if you aren't upgrading the pg spot you need to upgrade the bench mob.
Also, seeing what guys are being paid, Knight's contract is actually not that bad. It is $13m, $14m, and $15m over the final 3 seasons, and having seen what some mediocre talent is being paid, Knight's contract isn't all that bad. His contract is the 67th highest in the NBA, and while he isn't the 67th best player in the NBA, over the length of his contract his contract will fall in terms of being the highest paid. He is currently pegged between RoLo and JR Smith.
http://www.basketball-reference.com/...s/players.html