A full motion sim probably starts at around £400 an hour. I did my MCC at European Skybus (no longer trading) and they used to do quite well out of the gift voucher market for both their classic 737-200 sim, and their 747.
Also, a lot of people used to use it for interview prep for the likes of Ryanair. This is effectively "open to the public" as it's not exactly being used for a specific course, just some familiarisation.