flopped str8 on very drawy board

[teh_sponge]

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) pokerhand.org hand converter

Table is super donkish as can be seen by flop action. How much would you guys bet here, obv need to price out the draws???
CO ($57.30)
Button ($23.60)
SB ($4.90)
BB ($26.15)
UTG ($21.55)
Hero ($24.65)

Preflop: Hero is MP with 7[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $1</font>, CO calls $1, Button calls $1, <font color="#666666">1 fold</font>, BB calls $0.75.

Flop: ($4.10) J[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, <font color="#CC3333">Hero bets $2.5</font>, CO calls $2.50, Button calls $2.50, BB calls $2.50.

Turn: ($14.10) 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, <font color="#CC3333">Hero ???