Because RJ's contract is for just 2 more years not 4. So in the next 2 years if we don't end up with a le we can always have 2011 to sign another max player to pair with Tony for the future. We can't do that by signing someone with the contract like Jackson ( even though I would trade for him). And even though Jackson would cost 6.5 million less, it wouldn't really be if you look at it this way.
Spurs trade: Bowen, Oberto, Bonner, Mason
Milwaukee trades : Richard Jefferson
Milwaukee would buy out Oberto and Bowen to save 3.5 million on the books next year. Spurs would resign them for the minimum. So in essence Spurs really would be trading Mason and Bonner for Richard Jefferson.
Richard Jefferson would take Mason's minutes. So in reality we would only have to find Bonner's replacement, oh darn.
So yes it can be possible.
But all in all I'm down for Jackson or Jefferson or any move that would really improve our team around the big 3 for the next 3 years. All i know is our window is shutting fast and our FO needs to act quickly and rationally.