Paying to play at FLGS isnt something thats common here. I hear about it, but only tournament formats do it. RPGs are basically free first come first serve game space. Though, I could see a fee going towards the store and materials and helping keep attendance up.
I think the reason its uncommon here in the twin cities is we have not only a ton of gaming stores locally, but we have some with very large gaming spaces. We got the usual 4 table strip mall joints, but we also got like 2000 SQ ft gaming space joints that can really pack em in.