Is this river bluff brilliant or suicidal?

[B-Man]

Live 10-20, I start the hand with a little over 5,000, villain covers.

Fish in middle position bets 80, another guy calls, I call in the cutoff with 6 [img]/images/graemlins/heart.gif[/img]4 [img]/images/graemlins/heart.gif[/img], button calls, both blinds call, 6 players see the flop, 480 in the pot.

Flop:

J [img]/images/graemlins/heart.gif[/img] 8 [img]/images/graemlins/heart.gif[/img] 4 [img]/images/graemlins/club.gif[/img]

The blinds check, the fish makes a donk bet of 120, next guy folds. I raise to 420.

The button cold calls; he has been playing pretty tight and seems solid. Everyone else folds.

Turn (1,440): K [img]/images/graemlins/spade.gif[/img]

I am worried about the button’s cold-call, but if he has a draw, he does not seem like the type to call a big bet on the turn, and if I check, the hand is probably over. So I bet 800.

The button thinks for maybe 30 seconds to a minute, then calls.

River (3,040): 2 [img]/images/graemlins/club.gif[/img]

The draws didn’t get there, but I no longer put villain on a draw (unless he had something like 7 [img]/images/graemlins/heart.gif[/img]9 [img]/images/graemlins/heart.gif[/img]). He probably has AJ, or possibly a set, though I think he probably would have raised the flop or turn if he was that strong, so my gut says he has a medium strength hand. I have not been spewing and have only showed down good hands to this point, so villain probably views me as solid.

I bet two thousand.

Comments?