Speaking only for myself, there is no way in fuck I'd ever do a "pay to pitch" event. Startups are already hard-up enough for cash, and then you get some so-called "angel investor" who wants to make a profit off of simply allowing the unwashed mashes a few meager scraps of their attention?
Yeah "fuck you" to that Mr. Bigshot Angel Investor.
You should be grateful any entrepreneur is even allowing you the chance to enhance your deal flow and get in on their deal in the first place.