I see nothing wrong with it, looks nicely made. The price doesn't seem bad either honestly, I mean it wouldn't be worth my time to build those if I could only get 40 bucks for them, that's probably 30 minutes of labor and at least $15 in materials plus packing, shipping and ebay fees.
Wouldn't buy one myself, I'd just rig something up on the bench, but my test rig is not nearly as tidy looking.