LOVE my Pro. F$%^g love it. Out of the box, it's nothing spectacular. You need the mods for this game (LEDs, bell mod, train, sub, etc).
$4100 for an unmodded HUO is probably a touch high. Blinged out, you'll be in the mid-$4Ks. NIB is low-$4Ks.
Such a fun game. Good luck!!!
EDIT: I've had a ton of time on the Premium. Still love my Pro. Two very different games.