At Klosterwirt, it's € 8.60/Maß for Helles (same in the Ausgustinerkeller beer garden for Edelstoff). For € 9 you get Edelstoff even at Klosterwirt.
The Museum serve is not a Maß, that's zwei Halbe.

I guess Oktoberfest wages (which have always been quite high) are through the roof this year, even more so than wages in general, as are prices for electricity and gas. And then, just as with airline tickets and hotel rooms, as long as there are enough buyers at crazy prices, you'd be mad not to ask for those prices. Some of the prices offerendum has posted on recent trip reports were nothing short of indecent, so by comparison this is all right still.