22/180 facing a riverbet

[htoepidemix]

still early play and my image is pretty loose agressive
CO+1 and CO have been playing pretty tight, solid poker
PokerStars No-Limit Hold'em Tourney, Big Blind is t50 (9 handed) internettexasholdem.com

Button (t955)
Hero (t3285)
BB (t1745)
UTG (t1915)
UTG+1 (t943)
MP1 (t2600)
MP2 (t1775)
MP3 (t2660)
CO (t2040)

Preflop: Hero is SB with :7d, :5d.
[color=#666666]4 folds</font>, [color=#CC3333]MP3 raises to t150</font>, CO calls t150, [color=#666666]1 fold</font>, Hero calls t125, [color=#666666]1 fold</font>.

Flop: (t500) :5s, :qd, :7h [color=#0000FF](3 players)</font>
[color=#CC3333]Hero bets t250</font>, [color=#CC3333]MP3 raises to t500</font>, CO folds, Hero calls t250.

Turn: (t1500) :qc [color=#0000FF](2 players)</font>
Hero checks, MP3 checks.

River: (t1500) :td [color=#0000FF](2 players)</font>
Hero checks, [color=#CC3333]MP3 bets t700</font>, Hero???

Final Pot: t2200
the flop is just what im looking for.. i lead out looking to see if it hit villian or not. from his minraise i put his range on:PP,22-TT, AA, KK, (he's raised QQ to 4x BB)A7 or AQ -on the chance its AQ i dont think he's willing to get it all in here with TPTK - with the rainbow flop, and eliminating the CO i have no problem just calling here and seeing if i can get him all in on the turn
the turn card basically stops me in my tracks..
if he had AQ his just hit trips, and most flop options got worse. good too see he checked behind, but he has tried slowplaying trips like this before
i checked the river and he bets... im getting 3:1 on the call but, what am i beating??? thoughts?