Last year, Ainge offered six picks to move up from #16 to #9, and it didn't work. I highly doubt Sacramento does this unless the future first is something like a Brooklyn Pick or the future Memphis First Rounder (And I say no to that).
I'd rather keep Crowder and Bradley than get Butler. If we have to part with one, then I would part with Bradley, as Bradley becomes a Free Agent in just two years but we have Crowder on a team-friendly deal for 4 more years.
That being said, I would do:
#3, Bradley, Amir, Hunter for Butler and that's my absolute best offer. If they want more, then just hang up. I personally don't want to part with Bradley or Crowder to get Butler (Bradley and Crowder combined make less than Butler per season), but if it must be done, so be it.
I think if we give up Bradley we should keep Rozier as he's an electric player and if, god forbid IT or Smart got injured we need Rozier as depth.