$500 - xd45c or m&p45c
$1,000 - ar15
$1,500 - ar15 + xd45c/m&p45c
$2,000 - ar15 + xd45c/m&p45c + xd45c/m&p45c
$2,500 - ar15 + ar15 + xd45c/m&p45c
$3,000 - ar15 + ar15 + xd45c/m&p45c + xd45c/m&p45c
kinda lame. I think you ran out of ideas.
$500 - Glock or AR-15 or 590A1
$1,000 - HK45 variant or ar-15
$1,500 - Benelli m4 (eh, your gonna need 100-200 more bucks for this but its close enough; lets pretend its on sale)
$2,000 - HK Mark23 on the mainland with 2 or 3 new 10 round mags and shipped to Hawaii or IWI TAVOR or a FN FS2000 Tactical
$2,500 - HK Mark23 in Hawaii (might actually have to spend 3k for this one here depending on who is ripping you off) or Scar17S or possibly a Salient Arms Glock 20 (I mean if you gotta blow $2.5k, why not do it on an over priced Glock which still has a 4.5lb trigger pull with tons of pretravel...?)
$3,000 - nothing really in this price range I can think of I would want, everything seems to jump to about 5k and for that amount I'd look at the DRD Paratus or the Nemo Omen (both just for shits and giggles; seriously, where could you possibly use either realistically?).