Solo travelers are still probably better off in hostels $wise, but if you have to pay for more than two beds, there are a couple of other options that can work out cheaper.
The Etap hotels are a really good deal - they have bunk beds (double below, single above), private bath, a little desk/TV stand, and that's about all, usually for between 30 and 50 Euro/night. Sometimes there is a supplement for more than one person in the room, sometimes not. The ones we stayed in, in Vienna and Salzburg, were about 40 Euro/night, including the multiple person supplement. We have to pay for 6 beds at youth hostels, so two rooms works out to less than 15 Euro/pc, with the advantage of private bathrooms and, well, privacy! They're usually a little out of the way, but ours were very easy to get to by public transit. We didn't pay for the breakfast, cause it was cheesy, but never had a problem finding something to eat nearby.
We haven't stayed in the Formule1 hotels, which are basically the same rooms but with shared bathrooms in the hall, from what I can gather. These are even cheaper, (usually around 30/night, for up to three people/room) and I've no doubt we'll be checking some of them out this summer, too. www.hotelformule1.com
Both of these chains are totally no frills (there's not even a reception desk), but they were inexpensive and clean, what more do you need?
Another option: we sometimes rent apartments if we're planning on staying someplace for three or four days, which gives a lot more space and privacy and also gives us the option of cooking in, which saves $$$ too. And it's nice to have a little room to spread out at the end of the day. Longer stays usually net a discount, and the apartments are often centrally located. The one we stayed in in Budapest was across the street from the main train/metro/bus station.