Its a free market and they can charge whatever they want. You're also free to buy your wood somewhere else (which you did). That's the beauty of capitalism. Long term the wood supplier with either succeed or fail with their new fee. And long term you will either return to them as a customer or find a new place to buy plywood
My system is all ungrounded PVC. I can count on one hand the times I've taken a charge from touching a pipe. For some reason the blast gates don't ever shock me and that's usually the only thing I'm touching. I do have one section of vertical pipe near my drum sander and table saw and I can feel the hair on my arm stand on end if I get too close to it right after running a machine for an extended period. I don't have concerns about fire issues because like Ross said...I've never once heard of or seen an actual incident occur...it's all theoretical as far as I can tell. I'm far more concerned about my DC sucking a spark off the bandsaw and dumping into the collection drum. Aside from not running the DC when running the bandsaw, I don't know what to do about avoiding that scenario.