NLCASH 0.50/1 - thin value bet?

[Poker monkey]

I'm new to heads-up cash games... should I have bet this river? Presumably checking behind on the turn is correct?

Opponent seems fairly loose and tends to bluff a lot although I haven't seen him on a check-raise bluff. In fact I haven't seen him check-raise at all. Probably because my style has been quite passive to exploit his tendency to try to buy pots.

Full Tilt Poker
No Limit Holdem Ring game
Blinds: $0.50/$1
2 players
Converter

Stack sizes:
Hero: $104.65
BB: $65.40

Pre-flop: (2 players) Hero is SB with 8[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/club.gif[/img]
<font color="#cc0000">Hero raises to $3</font>, BB calls.

Flop: 7[img]/images/graemlins/heart.gif[/img] 2[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/spade.gif[/img] ($6, 2 players)
BB checks, <font color="#cc0000">Hero bets $4</font>, BB calls.

Turn: 7[img]/images/graemlins/diamond.gif[/img] ($14, 2 players)
BB checks, Hero checks.

River: 8[img]/images/graemlins/club.gif[/img] ($14, 2 players)
BB checks, Hero checks?