Should I vb here?

Opponent is a complete unknown.

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

Button ($10.05)
SB ($27.50)
BB ($26.15)
UTG ($20.50)
Hero ($27.75)

Preflop: Hero is MP with Khttp://www.flopturnriver.com/phpBB2/...es/diamond.gif, Qhttp://www.flopturnriver.com/phpBB2/...es/diamond.gif.
1 fold, Hero raises to $1, 2 folds, BB calls $0.75.

Flop: ($2.10) Khttp://www.flopturnriver.com/phpBB2/...iles/heart.gif, 4http://www.flopturnriver.com/phpBB2/...miles/club.gif, 7http://www.flopturnriver.com/phpBB2/...miles/club.gif (2 players)
BB checks, Hero bets $1.5, BB calls $1.50.

Turn: ($5.10) 8http://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
BB checks, Hero bets $3.5, BB calls $3.50.

River: ($12.10) 9http://www.flopturnriver.com/phpBB2/...iles/heart.gif (2 players)
BB checks, Hero

Yes. ~$6.

I would too. hopefully you don't run into AK or something.