These responses are lol funny. Come on people, you expect someone to 3bet with A-rag? Key question is your own image at the table? Are you playing loose or tight, and what have you shown down with?

Even if you have enough info to tell this player is not tight, his 3bet range has to be somewhat tight. Unless he's stupid and trying to bluff, he probably has a decent starting hand in this spot out of position. It is 200NL, so i would expect him to have some sense.

Your raise is higher than the standard 2.5-3xBB range. This could be a tell if you've shown down a hand like AK, AQ, KQ, etc with that starting bet before. You are also cbetting the flop a little light. You are betting half the pot which can leave the door open for someone who believes they have odds to draw and will get paid off. 2/3-3/4 of the pot is a standard cbet on that board. The check behind is a fail here. You don't want to see a river. It should be shut it down, or double barrel. The river bet is smart on his part because you showed you do not have a strong made hand. He could easily bluff this, but the 3bet preflop is strong showing PP.