[Erwin]

London hotels are very expensive compared to what you get. Having stayed there many times I was always jaded about the more expensive hotels, but visiting luxury hotels in Berlin or Vienna is a much nicer experience, Hyatt or Sofitel (and sure, Mandarin Oriental if you can afford it). E.g. you can go to Berlin and stay at the 5-star Sofitel which has a top 20 (out of 800) hotel rating at Tripadvisor and pay 110€/night for a 4om² room. I've paid the same at a hotel without a window in London once.

Lisabon is another city good for cheap luxury hotels. Trivago is a great hotel aggregator.

[S4M]

Good point about the quality and price of hotels varying according to the city. Guess Airbnb business will be more successful in places like London than Berlin or Lisabon (Lisboa?).