I'd nix the money part. This is all about good communication. If you communicate your intention to help the person you're emailing in some way early then you've

I'd nix the money part. This is all about good communication. If you communicate your intention to help the person you're emailing in some way early then you've changed the whole dynamic of the interaction. If you say "I'm a smart guy looking to solve problems, can I pick your brain?" then you've hurt yourself. You've created a situation where you are asking for help and not giving it. If you say "I'm a smart guy who's been researching problems in your industry and would like to toss some ideas at you to see if they'd be helpful for people like you" then you've created a situation where both people benefit. You're getting your questions answered and the mark is getting ideas that could potentially help him too. This is a really simplified version but the idea of creating a relationship that benefits the other person makes it far more likely that they'll agree to what you're asking.