Charging for even a small carry on bag is ridiculous. I fly internationally three times a year and carry on only. I am currently in Europe, just flew Ryanair (which I hate) and had no trouble. I always use either a Goruck GR1 21 Liter (18 x 11.5 x 5.5 inches), or else a Recycled Firefighter 24 Hour bag (18 x 12 x 6 inches), and always place it under the seat in front of me. I understand that your mode of carry is probably different from mine, but charging me and those one bag carry on folks like me is a silly idea.