I agree they don't double dip, at least not that I can recall. But I wonder if this may end up being an exception? Maybe they could retool it to be dirty instead of clean? They have done this with the biker scout in a box set with the speeder bike, so why not the snowtrooper?
The price they are asking is pretty reasonable for the box, around $60 CAD but of course we'll not see them on ebay for that price. I think they got burned a bit by the last box set that ended up clearing and can now be had for cheap. The market for these is still limited and that's the beauty of the line to me, not everyone has one or army builds with them. If that had been another TRU box, army building might have been possible, but as a mail away, probably not.
As for the end of the line? I'm not sure, I think it depends on how much of the vintage line is left. Seeing that Droids 3PO in there gives me hope for more droids figures yet down the road. While I may not necessarily want them, there's still lots of Ewoks from ROTJ and the series to do as well. No Jabba yet either and still plenty of vague characters from the vinty line remain. Plus they can always either venture into figures not released in the vintage line (boo, to a degree) or go into the prequels (bigger boo).
The company has enough product out there that star wars is only one line of theirs. A larger line, but still only the exclusives plus two series with 7-9 figures per year. I think it still has some life. They aren't totally dependent upon star wars is my point I guess as there are other lines with more figures in them in total.