I went to Lindisfarne the best part of a decade ago and they have mead in a shop made by the monks. It was dreadful. Every one I tried was not good, and they were expensive. Can't remember the pricing, just the vibe. No idea how I'd price a niche product that was made with more love and less cynical marketing though...
With the right product and branding you could really charge anything £30/£40+, but on behalf of us buyers please don't take the piss because that's quite an interesting product idea :)