I worked on a hotel barge in the summer of 2015. It was definitely at the bottom end of the market at £850 per week, all inclusive including transfers. The boat took up to 8 guests in very cramped accommodation. The operation was basically a hobby and certainly wouldn't generate anything like a decent profit, if any. One problem was that the costs of transferring more than 4 passengers from Paris wiped out any profit from the extra numbers. Larger parties made a lot more work without generating any return and the need to accommodate 8 guests made it intolerably crowded. My advice, with deep reservations, would be to offer a modified 'holiday share' with guests responsible for their own transport and participating in the navigation, cooking etc. That way you would avoid the need to hire staff or run a large vehicle. This model would not appeal to the elderly, rich American market but you might find customers in the UK canal community who want to try continental cruising at a reasonable expense. The question of licensing, insurance etc would be a very grey area and need approaching with caution. By the way I was working 14 to 15 hours a day with half a day off a week, at best. It's not for the faint hearted.