nl 50: TPTK against station, Proper size for a value bet on river?

[Pokerdemic]

Villian was pretty weak, and playing at 40/0/1 over 50 hands. But I had seen him call down hands when he had a set and two pair. He snap called the flop and turn. I was wondering if I value bet this river, and what would be the proper bet size? River play on hands like this is by far my weakest spot, so suggestions will help.


Poker Stars - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 6 Players - (LegoPoker HH Converter)

SB: $49.50
BB: $56.45
UTG: $75.00
MP: $46.75
Hero (CO): $51.80
BTN: $41.80

Preflop: Hero is dealt A[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img] (6 Players)
2 folds, <font color="red">Hero raises to $2.00</font>, BTN calls $2.00, 2 folds

Flop: ($4.75) 8[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $3.00</font>, BTN calls $3.00

Turn: ($10.75) T[img]/images/graemlins/club.gif[/img] (2 Players)
<font color="red">Hero bets $6.00</font>, BTN calls $6.00

River: ($22.75) 6[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero?