What the Grizzlies saved in the Laker deal:
They shed $2,624,800 of salary in the deal itself (the difference between Gasol's salary and the combined salaries of Brown, McKie and Crittenton). Prorated, they would save about $1.15M for the remainder of this season.
They lose $9,825,000 off the cap this summer (Brown and McKie).
In total, they took $12,449,800 of salary off the books by July 1.
What the Grizzlies could have saved with the proposed Net deal:
They would have shed $2,123,420 of salary in the deal itself (the difference between Gasol's salary and the combined salaries of Allen, Armstrong, Krstic, Magloire, Nachbar and Wright). Prorated, they would save about $0.93M for the remainder of this season.
They would have lost $11,611,580 off the cap this summer.
In total, they would have taken $13,735,000 off the books by July 1.
McKie's salary was estimated at $750,000 by several reporters. The other salaries come from ESPN's Trade Machine.
The other consideration is that the Nets would have needed to send three more players to Memphis than the Lakers did, so the Grizzlies would have needed to release two players off their roster to make space for the trade, or send players like Andre Brown and/or Casey Jacobsen (both minimum, expiring contracts) back to the Nets. Including either player in the deal would have saved the Grizzlies even more money this season.
After the deal, the Nets roster would look like this:
PG: Kidd, M. Williams
SG: Carter, Jacobsen
PF: Boone, Williams, Brown
C: Gasol, Collins/Swift
That's just ten players. We're assuming they take back Jacobsen and Brown, since they would need to add players to their roster anyway, to meet the NBA minimum of 13. They would need to add three more.
Billy Thomas, Eddie Gill and another swingman from the D-League (Keith Langford?) would still need to be added.