If it can fire a lethal single shot on small game inside 50 yards I'd be interested for sure.
otherwise it is a pretty cool novelty item and if it can be done on that scale it could most certainly be improved to be more powerful and more accurate through projectile engineering and an external battery pack capable of being charged in a variety of ways including portable solar charging.
As a new and novel product I don't think the price is too out of line and I would expect to see the prices start to come down as more of these types of "guns" come to market.