That seems kind of strange. Unless they were already planning a trip before you started talking and it just works out that they can meet you while they're in town. 

As you said, I would want to learn more about the person before investing in a meeting.

I would just voice your concern and ask them why they want to meet so soon without really knowing much about each other. It's an honest question and if their answer seems weird to you, maybe call it off. Listen to your instincts. 

On the other hand, maybe it's "love at first sight" and they want to snatch you up as soon as possible. 😃