Chronic "bet minner"

[22suited]

My read on this guy is that he raises min or bets pot preflop, min or pot at streets. Bet mins usually means he thinks he might have the best hand, but it can also mean he has an extreme hand like top trips or nuts. Ace high or middle/bottom pair can also be the case. Everyone is at about 1500 but I am at 3000 from busting a trips to my flopped full house. Blinds are 10 20, preflop im UTG and limp with 44. He raises min, bb and I call.

Flop (board: 9s Kd 8d):

bb checks. hero checks. villan
checks.

Turn (board: 9s Kd 8d 5h):

bb checks. hero checks. villan
bets 20. bb folds. hero calls.

River (board: 9s Kd 8d 5h 4h):

hero bets XXXX.

What would you do in my position at that river? Pot was 170.