[ChrisV]

That's fuzzy thinking. +EV is +EV. The amount you've already invested in the pot is a sunk cost and not relevant.

It's true that the equity from call is pretty slim, but remember that the problem only says that you've previously seen him do it with AQ+, JJ+, not that he definitely won't do it with any other hand. Adding even one junky hand to his range (98s, say) increases your equity to 42.88%, at which point you're throwing away around $93 in equity if you fold.