20+2: agg. blind player 3 barrels - decision with TPWK

[BarryLyndon]

Villain tried to bluff a midpair on a 10 4 5 8 2r board. I had a 10 and called him on the river. The action when V bet 1/2 pot on flop, then checked the 8 turn, then bet 3/4ers pot on river. He had 77, so I'm pretty sure he was turning 77 into a bluff. Also, that he limps with good hands.

Villain1 (1200), button

Villain2 (3900), SB

Hero (2900)

Blinds 50/100


Fold, Villain2 completes, Hero checks with K6o

Flop: K J 2r

Villain2 leads for 100, Hero calls

Turn: 4 completes rainbow

Villain bets 300, Hero calls

River: 2 d (no flushes)

Villains bets 600, Hero ?