The Wizards are actually adding a little bit of salary this year, though the final number may change if Barbosa and Collins accept buyouts. Crawford is making just under $1.2 million this season, whereas Barbosa and Collins were both making just over $850,000, the veteran's minumim. Combined, the Wizards will actually add about $500,000 to their books this year, pro-rated over the rest of the season.
Again, that number may change if the Wizards agree to a buyout with either player. Regardless, the Wizards will not save or add significant salary this season with the trade.
About the only possible benefit to this deal: the Wizards will save some money off next year's payroll. Crawford was expected to make just under $2.2 million next season, whereas both Collins and Barbosa are expiring contracts.
But how much will this actually impact player movement? The Wizards were slated to pay out about $59.6 million to 10 players next year prior to the trade. (They also owe Andray Blatche $7.8 million after letting him go via the amnesty clause, but this does not count on their cap or for luxury-tax purposes). Without Crawford's salary, that drops to $57.4 million. Those numbers assume that Emeka Okafor and Trevor Ariza do not exercise early-termination clauses and become free agents -- the two are slated to make $14.5 million and $7.7 million next season.
Is that difference significant? This year's salary cap came in at around $58 million, so the Wizards won't be getting any real cap space out of this move. They will potentially receive some more wiggle room to use the mid-level exception without worrying about the luxury tax, but they were slated to be comfortably under the line anyway. The Wizards don't pick up any additional trade exceptions beyond the $1.8 million one they already have, which expires right before next year's draft.
So ... it's something, but it's not a whole lot.