Looks pretty interesting and the price is reasonable. I'm with Brian...possibly better for jewelry or smaller items.
The same maker's hobo nickel vises are also interesting.
It looks very nicely made but I'm with Sam & Brian in that it looks best for jewellery. Not sure I'd care for a metal to metal contact on the ball, I'd prefer the good old rubber tyre. The hobo nickel vise looks really neat but it's a lot of dough for something that is dedicated to only nickels. I'll stick with my usual vise and a block of wood with hot glue!