Straight but is there value in a bet?

[jessyj07]

Villain is around 28/2/.6 after a couple hundred hands. I wanted to push the river but is there value in it? I can't imagine that a worse hand will call [img]/images/graemlins/confused.gif[/img].

PokerStars No-Limit Hold'em, $0.25 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($24.75)
Button ($81)
SB ($24.65)
BB ($29.85)
UTG ($44.80)

Preflop: Hero is MP with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/diamond.gif[/img].
UTG calls $0.25, <font color="#CC3333">Hero raises to $1.25</font>, Button calls $1.25, <font color="#666666">2 folds</font>, UTG folds.

Flop: ($3.10) 5[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $2</font>, Button calls $2.

Turn: ($7.10) 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $4</font>, Button calls $4.

River: ($15.10) 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero bets or checks?

[shoxbb6]

I bet more on the flop/turn and check/call river