Hrmm, this is a ~2 square foot Savonius type VAWT with max rating of 12-16v and 4A suggesting ~48W, theoretically @ around 10m/s. If this is the case then the overall CP has to be at least 0.40, a figure I find difficult to believe. I would guess the actual CP is closer to 0.20 than 0.40, and that the 50W rating is simply the alternator max capacity. If we work with the idea that the CP is ~0.20 then the swept area leads us to an 8-10m/s wind delivering 12W-22W. @ ~$260.00 US, this brings us to $21.66/W to $11.81/W. In the more typical 5-7m/s winds we might hope to get 3W-8W. Of course if you are in a high wind area then 22W * 24 hours = 528Wh, it would take an 90W solar panel to produce the same 528Wh in 6 solar hours, so from this point-of-view it is a "bargain". Even at 8W * 24 hours, this is 192Wh, and a comparable PV panel would have to be at least 32W (again assuming 6 hours of insolation) to match it's output. I think a Lenz II design could improve on performance in the price category and be made to store in roughly the same space. If you take six Lenz II design "winglets"; removed from the turbine they would store nicely in a round tube. Snap two "winglets" together to make a single longer "winglet", and attach the "winglets" to the central hub with quick disconnects and you could easily assemble a VAWT with a swept area of 24 square feet (6 feet tall by 4 feet in diameter.) With an overall CP of 0.20, this should yield 32W @ 5m/s, 142W @ 8m/s and 270W @ 10m/s. In a medium volume production setting it is likely you could make money selling such a rig for $300-$500 US.
I will say it is good to see that someone is at least attempting to produce a commercially viable VAWT :-)