I have spent many months riding around the continent, and I always stay in hotels. However - I avoid chain hotels (Accor, etc.) like the plague.
If I want to spend an inexpensive night somewhere, I will head for a smaller village and look for a pension or perhaps a 'town pub' that also offers rooms. My experience has been that this is always less expensive (and far more pleasant) than any Accor-type hotel. An additional bonus is that the security available for my motorcycle is also much better - usually I just roll it around to the back of the building and it is out of everyone's sight.
In southern Germany, in the Black Forest region, there are many hotels that cater specifically to the motorcycle community, they are usually inexpensive.