Current Roster
1. Rose - $15.5M
2. Boozer - $15M
3. Deng - $13.3M
4. Noah - $11.3M
5. Hamilton - $5M
6. Korver - $5M
7. Brewer - $4.37M
8. Watson - $3.4M
9. Asik - $2.3M
10. Gibson - $2.1M
11. Butler - $1.08M
12. Lucas III - $900K
13. Scalabrine - $850K
This roster comes in at a shade over $80M. You can trade out one of Korver/Brewer/Watson for the Bulls 29th Pick, but chances are you won't get the same level of production. Even if you do, the savings is at most $3.5M and will mostly be offset by Asik's contract increase, still leaving the team well over the luxury tax threshold.
Adjusted Roster
1. Rose - $15.5M
2.
3..
4. Hamilton - $5M
5. Asik - $5M
6. Draft Pick #5 - $2.8M
7. Draft Pick #7 - $2.3M
8. Gibson - $2.1M
9. Butler - $1.08M
10. Draft Pick (#29) - $857K
11. Draft Pick (2nd rd) - $800K
12. Vet Min - $900K
13. Vet Min - $850K
In this scenario the Bulls trade Deng and Noah for draft picks. The draft picks aren't replacing Deng and Noah, rather they're take the spots of Korver/Brewer/Watson.
The Bulls know the level of performance they'll get out of the existing three role players, while the draft picks potential ceiling is MUCH higher. Even if the picks' ceiling isn't achieved their floor only needs to match up with Korver/Brewer/Watson's output to have replacements on smaller contracts.
The total for the adjusted roster comes in at a tad over $37M, leaving over $20M before hitting the salary cap, which can be exceeded by utilizing the trade exceptions generated by the Deng/Noah trades.
In the end, do you gamble and hope the dropoff from Noah to Asik and the loss of a known bench quantity can be overcome by the Bulls upgrading over Boozer, Deng and a lottery-pick filled bench?
And even if it's a wash, the latter roster costs much less than the former.