The link is totally credible. I am not 100% sure of the costs, but people in my club continue to go back year after year and LOVE it. What they do is go to England/ Wales/ etc. They will put you up in nice hotels. If your wife or husband doesn't detect they have other arrangements made for these folks who want to travel with you but not detect. They take them on tours of the old castles and historical places and shopping areas. The TH'ers are taken to farm fields that are secured ahead of time with the farmer. After their harvests are over they give permission to this group to come out and hunt (I'm sure they are paid for the rental of their field, but that is not your problem). In England, there are laws relating to treasure, so a group of experts sets up a tent on the sidelines of the field and anything found has to be turned into them to authenticate and appraise. I think this is explained in more detail on the website, but you can keep some of your stuff and some may be returned at a later date. Apparently you don't have to donate it. These fields are the same fields that the Crusades were fought on or soldiers have marched on for 1000's of years. What you find is mideavil stuff. One of our guys found a Heraldic Shield Crest that could be traced to the very soldier who wore it into the Crusades! The museum kept this item (I think he donated it), but the guy who found it got a very nice plaque to hang on his wall that had a real nice photo of the piece and an explanation of it's signifigance. He also got credit for the find in the local museum.
Others in our club have found hammered gold and silver coins and artifacts. One day I would love to have the $ to go and do this. Unfortunately by the time you have the money you are 65+ and don't have the energy! 8)