Yes, without a doubt you trade a top-3 pick for Cousins.
What I find interesting is combining your last two posts regarding the Nets pick. Let's imagine that we luck out and get the #1 overall pick, and Philly ends up getting pick number 3,4, or 5 either with their own pick or the LA pick.
If they would offer us Noel and pick number 3, 4, or 5 for the first pick in the draft (or even Noel and their pick for both the Nets and Dallas pick that we'll say is #9), would you rather have that package or trade the #1 pick with Sully and Amir for Cousins?
That's a tough choice for me. Though I'd love to have Cousins, having the potential to nab Noel and a Brown or Ingram type would possibly be worth passing on Cousins for. This potential lineup could be sick for a long time:
PG: Smart, IT
SG: Bradley, Rozier
SF: Brown/Ingram, Crowder
PF: KO/Sully
C: Noel, Zeller