What does villain have? $55+R+A

[beenben]

you should have some kind of a read - how'd he lose 600 chips in 12 hands? chasing? played one hand and folded to a raise? of course reads are kind of useless in a rebuy period could be anything from 45 63 66 33 Qx. slow played AQ or overpairs are unliikely. since you're posting this, I'm guessing 45.