I'm looking into a studio near my office to take some classes in addition to the ones I take at my ballroom studio.

This place is invitation only, charges a $100 annual membership fee, and sent me a questionaire asking about my interest and experience in tango but also what I do for a living.

I'm not quite sure what to make of this. Are membership fees the norm at indy tango studios (I'm in the US)? I also wonder about them asking what I do for a living, like are they trying to determine if I'm a good sales prospect of some kind?

I can see them doing some of this if they want "serious" dancers only, but it makes me a little uneasy. Am I being overly cautious?