Who cares? I see no problem with wanting to "hustle" the 205+ average guys. Now, if he was only watching 150 average bowlers, claiming to be mediocre, & possibly talking them into pot games, thats another story.
Maybe he is somebody thats REALLY good, as long as he sticks to bowling the top guys around, i see no problem with it.
Although, the easy solution is to ask him if he would like to bowl a few games with u. If he brings up money, say "sure, but only $5ish a game, i cant afford more" or something. If he still wants to bowl, hes probably legit. If he bowls poorly, then pulls the old "let me have a chance to win my money back" routine, give him 1 more game. If at that point it blows u out, hes a hustler, walk away & warn others.
This doesnt have to be such a mystery, ask the man to bowl & find out whats up.
Shawn