The standard MS complete unit from that seller is $270, so you're paying $130+ for the MS2 board, which is a rip off. When they are "in stock" again they will be $72 from B&G. If you want a system that hasn't been developed enough yet software wise and want to pay this guy an extra 80%+ over what it roughly should cost then go for it.
However, if you're a developer wanting to get a head start, then I guess it may be worth it, because at $130+ it would be slightly cheaper than routing, printing, and assembling an equivalent copy-cat board.
