Thanks for responding, Christi- yes, that makes sense. (And even if it didn't, you are of course to make your own business decisions however you want.)
The flat rates at the hotels just seem really unreasonable; because there is no way small ops can cover the volume of divers to be worth it. It just surprised me that the downtown pier charged both a flat rate and a per diver fee. But I suppose with so many downtown hotels feeding divers to that pier, the volume works out.
The Op I chose to dive with gave me a very short list of places she'd pick up, and I don't recall that the downtown pier was on it. We were otherwise told we'd have to taxi to the marina. That's one reason we chose an AI, the cheaper downtown hotels, once combined with cab fare, would cost us a lot more. She told us in advance we'd be responsible for the $3 pier fee. (Which hopefully hasn't changed to flat rate by the time we get there, though we'd pay that too.) At least they only charge you daily and not to get on and off the pier
Taxi fare gets you both ways.