Is there a local plywood supplier who's open to the public?

Basically just the title.

I'm not a professional cabinet maker, but I'm taking on a large-ish reno where I'll be building cabinets for my home. I don't want the overpriced trash from the hardware store, but I need plywood.

I'm sure there are local suppliers for cabinet makers, but the only ones I can find don't appear open to the public. Are there any professional cabinet makers who know of a place that is open to everyone (even if, presumably, they don't cater to people like me)?