$16 3 handed vbet riv?

[vers]

Hey. Opponent is the bad kind of lag. After he checks turn and riv is pretty safe I figure vbet is good. When he minraises I'm not ahead of much but pot is so big, can I fold?

PokerStars Tournament, Big Blind is t200 with t25 antes (3 handed) Converter on pregopoker.com

Button (t1540)
SB (t7685)
Hero (t4275)

Preflop: Hero is in BB with 6[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/diamond.gif[/img]
<font color="gray">Button folds</font>, SB calls t100, Hero checks

Flop: (t475) 6[img]/images/graemlins/club.gif[/img] 8[img]/images/graemlins/spade.gif[/img] 4[img]/images/graemlins/heart.gif[/img] (2 players)
SB checks, <font color="red">Hero bets t300</font>, SB calls t300

Turn: (t1075) J[img]/images/graemlins/club.gif[/img] (2 players)
SB checks, Hero checks

River: (t1075) 2[img]/images/graemlins/club.gif[/img] (2 players)
SB checks, <font color="red">Hero bets t500</font>, <font color="red">SB raises to t1000</font>, Hero calls t500