You know, if you've got a pet store willing to take them, give the eggs to them. Even if they do end up feeding fish (although usually, they're used as tank cleaners), that would a natural progression of life... (IMHO).
That being said, the other thing you could do is destroy the eggs. In nature, many of them would get destroyed (eaten, destroyed by passing animals, landscape problems, etc...) and thus, you doing this would be less harmful than suddenly having too many snails which you can't handle.
I wouldn't, however, "release them into the wild" - aka another body of water - because they could, potentially, cause problems, the effects of which may not be known for years and years, esp. if you put in a ton of these snails (it seems to me that you're dealing with a large amount here..).