Sarira:
I don’t think Egged is a money maker but even if it is that’s not the point. EVEN if it was non-profit, people consider it a public service and therefore would be up in arms if they charged extra. You need a reason to justify charging the customer more when the customer is receiving an identical product as a regular Erev Shabbos. Like I said, in Israel the Mikvahs do NOT charge more. According to your logic they should feel comfortable charging more but they don’t. Try to understand from a Mikva goer point of view.