Hotels in Ypres are actually really cheap. I’m seeing prices in the $100-200 range for some really plush looking hotels in the heart of the downtown district. For Europe, that’s pretty good. I would venture a guess that a cultural and business hub like Brussels would probably have similar hotel rooms in the $300-400 range and a similar hotel in London would cost you $400-1000 a night depending on what neighborhood it’s in.
That being said, with centenaries looming hotels may be in short supply, though I’ll probably miss the anniversary of the Second Battle of Ypres by a month or two since I need to consider my schedule. But this year’s centenary doesn’t seem to be affecting things too badly so that’s very promising (part of the reason Dad and I decided not to do it this year is because we expected the centenary of the first battle to cause crowds to swell year-round). It seems that even if it does get difficult to reserve a room and prices go up during this summer, there will be a clearly-defined “off season” that will give me more options. I’d rather not travel there during the fall or winter since Flanders is a pretty bleak place in Winter, but if that’s more doable that way, I’m open to it.