Sad to say it, but just letting everyone expire could leave us with the 15th pick in the draft. Blow it up now, and we're looking at more like #7 or #8. That's a world of difference, especially if we can package our picks and get into the top 5 or 6. We would have a ping-pong chance of top 3 as well.
Collectively if you traded the entire Big 3 and netted a 1st round pick, then we have $40M in cap room, 3 picks (at least 1 in the mid lottery), Rondo, Bradley and JJ.
Let's say you turn our 2 highest picks into Barnes or Gilchrist, around #6. Sign Eric Gordon ($15M), Jeff Green ($5M) and Dwight Howard ($17M).
Rondo / late 1st rounder
Gordon / Bradley
Barnes / Green
JJJ / MLE veteran
Howard
I find it almost impossible to come up with scenarios that good if we just stand pat and wait. Our running game would be unbelievable with Gordon, Barnes, Green, JJJ, Howard... we've got shooters, defense, rebounding...