Early stages of Sky's Main event BH. Player is a tight regular. I can't think of many hands we beat by the river apart from AcA
Would be interested to hear peoples views on all streets
We are in the SB with pocket

,

Blinds 15/30
UTG raises to 90, everyone calls, we call SB, BB its a total nit and folds.
5 Players to the flop.

Checks to UTG he bets 240 half pot. Folds to us we call.
Turn

He bets 720. 3/4 pot
We call
River

he mashes the 3/4 pot button again. The bet is 1800
Kinda looks like the nuts or almost nuts
I'm not exactly loving life in this spot. I originally thought that I wouldn't be folding here, but the bet sizing seems like he has it and thinks betting full pot will just give it away, and half pot is too small so he's trying to come to a balance between the two to extract max value here.
Getting almost 2.5/1 on a call, but I just don't think we have the best hand here often enough to justify it.
If he's a tight regular, then I don't think he's going to be betting 3 streets with

for example.
I think it's a reluctant nitty fold for me.