(55) Top pair plus nut flush draw ITM, call turn all-in?

[Slim Pickens]

Button is loose-passive.

Party Poker No-Limit Hold'em Tourney, Big Blind is t200 (3 handed) internettexasholdem.com

BB (t2715)
Button (t3060)
Hero (t4225)

Preflop: Hero is SB with 5[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img].
Button calls t200, Hero completes, BB checks.

Flop: (t600) K[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets t600</font>, BB folds, Button calls t600.

Turn: (t1800) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t1000</font>, Button raises all-in [t2260] , Hero has to call t1260 with about 5000 in the pot.

Correct me if I'm wrong but have to almost 100% sure I'm beat here to fold. Folding would be moronic, right? Preflop, is raising a better option than completing?

EDIT: fixed pot amount... it's even worse than I remembered. Nice to know I'm not making incorrect instacalls.