Honestly I'd make your own, you can get all the pre-cut leather straps for £5 on ebay... the studs are pennies and the tools you need (hole punch, leather awl, press stud tool, burnishing tool) are all cheaply available. In total you'd definitely spend about half what that guy is charging and you would have the proper width belt of 2" as opposed to a narrow 1.5".
When making my belt I think I spent in total about £20, and I compared 1.5" to 2" belt straps (1.5" is cheaper and easier to find, hence why this guy is using it) and there is noticeable difference once you put the studs and outer leather strip on (unless you use a crazy narrow outer strip) - the belt just looks really small and out of place imo.