Brothels, Buffets, and Disneyland

I read in a local newspaper about a bordello in Germany, where prostitution is legal, that charges customers a fixed fee: a bit over 100 euros ($140) for an evening of drinks, food, and entertainment.
This kind of pricing is common to amusement parks (Disneyland, for example), ski lifts, all-you-can-eat restaurants, and elsewhere. It is a way the firm can minimize the transactions costs of pricing each service and also, if the fixed price is set properly, extract the entire consumer surplus.
With such a pricing scheme, however, the customers who choose to pay the fixed fee will differ from those who buy the product if each item is priced separately. Visitors to Disneyland will disproportionately be those who will consume a lot of rides, skiers will be those who want to make a lot of runs, and bigger eaters will visit all-you-can-eat restaurants (for example, I never go to them because they’re a bad deal for me).