I picked up flights to Spain for €9.80 each way, all in, except for cc charge in the previous sale just before the 30% off sale. I had been watching them daily and two hours before the sale ended I picked them up. The price actually increased in their next 30% off sale. They are back down again now but with not as much choice available.
They also have their last flight of the season going to Saltzburg for €13.99 all in (this has actually gone up by €5 from what it was two weeks ago) You cannot get back from Salzburg with Ryanair though, but you could split your break between Salzburg and Munich and fly out of Memmingen for €16.99. Pretty good value for €31 I would say.
Pick up a budget hotel in both locations and you could have a holiday in both Salzburg and Munich for two people for a week, for less than €500.