(10+1) flop top set... fold turn?

[bjb23]

Party Poker No-Limit Hold'em Tourney, Big Blind is t30 (9 handed) converter

MP2 (t865)
Hero (t1020)
CO (t535)
Button (t770)
SB (t430)
BB (t830)
UTG (t1675)
UTG+1 (t735)
MP1 (t1140)

Preflop: Hero is MP3 with T[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">4 folds</font>, Hero calls t30, CO calls t30, Button calls t30, SB completes, BB checks.

Flop: (t150) 3[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets t75</font>, CO folds, Button calls t75, SB folds, BB calls t75.

Turn: (t375) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets t300</font>, Hero???

ok, and a hypothetical: say i had top set and bet out with two callers(as above), but this time im first to act on the turn when the flush card came. assuming the same pot size, would you fire another shell to see where you are (if so, how much?), or check and see what the two callers do?

any thoughts on this hand would be greatly appreciated.

edit: added buyin