I mean, those guys are below average values for those prices, but surprisingly not by that much.
The thing about the NBA is that cap room is nearly worthless (with this summer being the exception). So if you have the choice of adding a Joe Johnson or Rashard Lewis with the only opportunity cost coming at the owner's expense, I think it's a move you have to make. In the last decade, who were the best FA signings? Off the top of my head, you have T-Mac, Nash, JJ, Boozer, and Lewis- so if you pass on a Lewis or JJ, what are you saving up for? I'm not counting Billups because he was a lottery ticket, and for every Chauncey there are like 20 Brian Cardinals or Mark Blounts.