I think your conclusion based on one show (even though it was a Regional) might have to be marked "insufficient data."
Not all modelers who bought WnW kits enter contests, and as for the H-B w.12 and Brisfit, they're not that popular among WWI enthusiasts (just look at the WnW Sold Out list to see what IS). Basic market forces are at work here: kits get sold out because they're in demand, and demand doesn't decrease, so the price rises. Conversely, those still available from WnW are so largely because the tiny demand (at least at that price point) was met long ago. Sir Peter decides what WnW produces, and many of those kits would NOT top the list in a poll of kits desired by internet modelers. I'm predicting that the WnW Camel will go quickly once it goes on sale, regardless of increased prices and lack of free shipping, ESPECIALLY since we know that the number of kits produced will be finite. And in that case, you may be right about some "buying to flip."
When WnW does add shipping costs to their recent price increases I wonder what will happen to WnW sales in those countries where the buyer must reckon on high taxes, import duties, and other fees. But I'd bet that, even then, Camel fans will make adjustments in order to buy them (I'm saving my pennies for at least two).
Respectfully,
Rob