I've recently observed with the SMT (remotely). It's a good telescope and you all do a great job running it!
(it seems that gasoline station owners here in Massachusetts got a different memo, though)
Despite the fact that the outcome is similar, there's a legal difference between "surcharge for credit" and "discount for cash". The former is/was illegal, the latter is legal. Presumably gas stations in MA and elsewhere are doing the latter.
This place just isn't big enough for all of us. We've got to find a way off this planet.