25/50 set vs river overbet

[holla-at-yoboy]

Villain is fairly new to the table and I don't really have any reads other than he's been fairly active so far, though he could just be catching, and I know he's a decent player. First couple streets are standard. I thought about a blocking bet on the river but decided there was a good chance he would raise a bet resembling a blocking bet and then I'd be completely lost, checking also of course gives him a chance to bluff. He surprises me with the overbet which I wasn't expecting to see. As played, call or fold river? If you like a blocking bet more lemme know, I think at this point I could go either way.

PokerStars No-Limit Hold'em, $50 BB (9 handed) pokerhand.org hand converter

CO ($10776)
Button ($1000)
SB ($8386)
BB ($1280)
UTG ($4950)
UTG+1 ($850)
MP1 ($1697)
MP2 ($5813)
Hero ($8280)

Preflop: Hero is MP3 with T[img]/images/graemlins/spade.gif[/img], T[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">4 folds</font>, <font color="#CC3333">Hero raises to $200</font>, CO calls $200, <font color="#666666">3 folds</font>.

Flop: ($475) 7[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $300</font>, CO calls $300.

Turn: ($1075) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $700</font>, CO calls $700.

River: ($2475) A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets $3000</font>, Hero?