The ppl saying, that the number of trials doesn't matter, your expectation is the same, may be should think about "Kelly Criterion" ideas.

There, if you have a limited bankroll, the optimal way to grow it, is not to risk so much, and reduce variance.

Isn't the single shot at this player, analagous in a way? You have a one off opportunity, and theoretically a 60:40 edge, therefore by same reasonibg as Sklansky Advanced Tourney book, your call should be made with a hand that has at least a 60:40 edge over a random hand.