Very thorough, I didn’t imagine you would go through all those details, I feel kind of sorry because I would have been satisfied with much less.
Indeed the prospect you outlined starts from the point where -say- Generation headquarters have to take the decision of starting a production line of cheap low whistles.
Of course the costs I previously categorized as “irrelevantly more expensive” are not so irrelevant from a starting point, moreover so in a market that has not the necessary appeal to invest in low whistles.
Well, if there was a market those costs would be really irrelevant, hell, Generation could even employ new people further helping the economy! 
Kidding aside, yes, there are costs that should be taken into account and your analysis is strong in underlining those costs, but if we look at the thing from a starting point of view, than how much would cost for a new brand setting up a high whistle production line?
Certainly less than a low (in this market), but their whistles would unlikely come out as cheap as a Generation or a Waltons or a Feadog’s and the like.
I would have imagined an already functioning department of Generation that made low whistles from the beginning and that way, most likely, we would have something that, like for the cheap high models, is fair to good (maybe also with the option of Freeman tweaked versions) and decently cheap.
The reason why such a department doesn’t exist (making a starting line even more difficult) lies in the market as you initially suggested and I’m now convinced that you are very right.
Who knows, maybe if we suggest to every new tin whistle player to play the low as well, in a few years we’ll have a whole new plethora of cheap low whistles, although (hopefully) by than I’ll be better at playing and most likely more demanding and aiming at something pricier!
I never thought that a low whistle would be the same price or even less that a high one, although from my words above we can take the reasoning to an extreme of lows costing less than highs just because the market says so.
Still that “significant factor” in the right conditions can be, as explained above, less significant making the low whistles’ price just slightly higher than that of high whistles.
I dare say that those 25$ (less than 20€ and slightly more than 15£ so that many don’t have to go convert currencies) are not a mirage if they (Generation, Clarke, Feadog, Waltons, Oak etc.) decide to sell them.
Who knows, maybe they don’t even need to change machinery for a production line and them we can even hope for a little less.
I would buy them and so would all of us because no matter how many Copeland and the like we have (or can have, I have none), we’ll always want to try all the cheapies we can as well, that’s why it is called Whistle Obsessive Acquisition Disorder.
