Lot's of VC firms do fish for information. I don't have much experience, but I would say "We're very busy right now and as a bootstrapped startup, all availabl

Lot's of VC firms do fish for information. I don't have much experience, but I would say "We're very busy right now and as a bootstrapped startup, all available funds are funneled into improving our product and delighting customers. Airfare isn't an affordable option right now, but I would love to meet the next time you are in the area." If they really are interested, they will offer to pay for the tickets right there. If they aren't serious, then they probably won't.