Nut straight meets runner-runner flush, value bet anyway?

[roggles]

I am wondering if betting half pot on the river and folding if raised is a good line

Full Tilt Poker
Pot Limit Omaha Ring game
Blinds: $0.50/$1
7 players
Converter

Stack sizes:
UTG: $61.80
UTG+1: $42.50
roggles: $99.85
CO: $276.10
Button: $38.90
SB: $31.75
BB: $91.50

Pre-flop: (7 players) roggles is MP1 with 8[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/club.gif[/img] T[img]/images/graemlins/spade.gif[/img] T[img]/images/graemlins/club.gif[/img]
UTG calls, UTG+1 folds, <font color="#cc0000">roggles raises to $4</font>, CO folds, Button calls, SB folds, BB calls, UTG calls.

Flop: 3[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/spade.gif[/img] ($16.5, 4 players)
BB checks, UTG checks, roggles checks, Button checks.

Turn: Q[img]/images/graemlins/diamond.gif[/img] ($16.5, 4 players)
<font color="#cc0000">BB bets $5</font>, UTG folds, <font color="#cc0000">roggles raises to $20</font>, Button folds, BB calls.

River: 7[img]/images/graemlins/diamond.gif[/img] ($56.5, 2 players)
BB checks, <font color="#cc0000">roggles ...</font>