Weight of the meal is important... but BPs should NEVER be on pinkies in the first place, so even a bunch of them wouldn't really give enough nutrition.

Best thing to do is find someone or somewhere that might take the pinkies you have and get some hoppers. Start with small hoppers and see if he'll take it. If so, do a few feedings on hoppers and then move up again to small adult mice if he'll take those.
Again, most newly hatched BPs take hopper mice right away, so anything smaller isn't a meal for them even in larger quantities. And it's not really a good idea to feed too many items at once.