I did the 21 Best of Europe solo in 2014. Even now with 10 tours under my belt, this is probably my favorite. As another RS guide told me there are blockbuster sights every single day. He was right!
I do always pay for the single supplement. I don't know if I snore - probably do, lol, but I just need some alone time after a day with the group.
As far as bed size, let me see what I can remember:
Haarlem - Ambassador - double (or maybe queen?) bed
Bacharach - Hotel Kranenturm - single
Reutte - Hotel Maximilian - single
Venice - Hotel Mercuris - I ~think~ this was a double but not 100% sure
Florence - Hotel California (hahaha) - double or maybe a queen
Rome - Hotel Nardizzi Americana - double
Monterosso al Mare - Hotel Punta Mesca - double or queen
Stechelberg, Lauterbrunnen Valley - single (I think the tour group may not use this location? I heard they were going to move the tour group up to Muerren. This hotel was a shared bath hotel for many of us.)
Beaune - I can't remember the name of this hotel. I do remember I had a double bed here
Paris - Hotel Beaugency - double
**editing to add: The RS tours don't always use the same hotels, so I really just gave you the names so you would have an idea of what they were like.
I felt like every penny I spent on this tour was worth it. I also stayed extra time in Paris and added the Best of Paris on after. I WISH I had spent more time ahead in Haarlem. I did not allow myself but one night ahead here and spent that day in Amsterdam. I regret not spending at least a full day in Haarlem.
I did not spend that much extra on meals and other costs. I think my daily average was maybe 20-25E. Rick often says to plan on 50E per day for extras but I just didn't spend that much. I did not rein in my spending either, lol! I did the gondola ride in Venice (about 25E each), went to a concert in Venice, spent money on gondola/cog train in Switzerland, did all the extra meals Dimitri arranged, did an extra wine tasting, etc.
Here is a Trip Report I did on this tour.