$5.50 sng AK button play, How confident are you?

blinds 10-20
Button: Hero (2300 chips) Dealt AsKc
BB: villian: 2700 chips
Pre flop
folded to hero on button raises to 60
BB villian calls
Flop:
Ac 3h 2d
BB bets 300 , hero calls
Turn: Ah
BB bet 300, hero raises 650 BB calls
River: 8d
BB bets 840 Hero????
do you push, fold, or call and why??
and also what are chances your beat and if you feel so can you still lay this down at the $5.50 level????