I went to the site. It's very basic but resourceful nevertheless. My only problem with it would be the weight of the support plus my HDV-FX1. It would be better if he could use lighter materials but I suppose that the building costs would rise.
If you look at a Glidecam 2000 pro, the other features are infinite balance adjustments laterally, longtitudinally and vertically. This means that the whole unit is in absolutely perfect balance. The other feature is the handle. It is in a slightly better place and therefore more comfortable.
All this said..........£350 vs £10??? - I think i'll try a home spun version first!
There is another design I came across
It looks a bit 'heath robinson' but again it was cheap.