Our beds in Munich during Oktoberfest cost € 40 this year. That´s just a few cent short of US$ 60 at the moment. Our competitors charge up to € 59 though - enough people are ready to pay that (or even more) but we think that´s in no reasonable relation to what they get, so we set the limit at € 40 for now.
I saw on Hostelworld that Meininger Berlin charged € 120 for a bed in a mixed quad ensuite on the finals weekend of the Football World Cup last year. I´m not sure though if anyone booked for that sort of prices. Many hostels were only half full during world cup - their expectations were just way too high. Many backpackers avoided Germany altogether because they couldn´t afford it.
I can confirm your rumor about Athens. Prices over € 100 were asked.
Prices not only skyrocketed in Athens, but all over Greece. It turned out to be a fatal mistake for Greece´s tourism industry - many People who went there every year (families and retirees above all) went to Turkey or Spain instead - and liked it there as well, many may never return to Greece.
I do not really think there is a general trend that hostels are getting more expensive. They only do in cities where real estate prices go up - so they have no choice.
In cities like Berlin I observe a diversifying market. Some hostels go for prime locations, invest lots in interior design and good service - and charge high prices (best example: Circus). Others, however, build huge beasts in bad locations (only an underground station must be nearby, everything else does not matter) and specifically target travellers who just want a cheap place to crash (best example: Generator). Both strategies work.