He wouldn't sign a 3 year $15M contract? What you think he's worth like $8M? The only team that pays him that is Dallas and I doubt they even do that considering they want Tyson Chandler back.. The only other team I could think if is LA..
I wouldn't mind Vasquez in a back up role. My top picks would be Ariza, Bradley, or Diaw but I don't see us getting either one for cheap.
He will get a contract that will probably be in 3yr $22M-$25M range. His last contract was for 2yr $13M. Thats more money per year than you're proposing. He got that contract after averaging less than 10ppg, 7reb and not to mention he didn't have 3 point shot. This year he averaged over 13ppg , 8reb, 3ast and shot the 3 @ almost 42%. Not to mention that he's not terrible at defense. He's and average defender. Take a look around the league. 7 footers get paid. Even Tiago Splitter will make $9.25M next year. You can also add NO, GS, CHA, UTAH, CLE, PHI and several others that could come into play depending on the draft and trades.