This discussion has been had here many times, but what my half-century of experience has taught me is:
With High D Whistles (and nearby pitches from Eb to around Bb) there’s usually isn’t a correlation between price and playing quality.
IMHO the best High D whistles ever made are the very best of the vintage Generations. IMHO the best whistle I’ve ever played in any key at any price is the Generation C got around 1980.
In fact when I started playing (1970s) the Generation was the only D whistle I saw anyone play. Your instrument-acquisition-arc went like this: as a beginner you got whatever Generation D you could find quick, then started a lifelong search for that Holy Grail Generation D. So, newbies and the Mary Bergins of the world all played the same whistle, but oh no certainly not the SAME whistle.
I’ve played, over the decades, several hundreds (maybe thousands) of High D whistles and none have quite matched my trusty old Feadog D got around 1980 EXCEPT a few quite superb vintage Generations which were the cherished possessions of fine players and not for sale.
The closest to those have been some of the Freeman Tweaked Generations I’ve played, and the whistles by Jon Sindt and some of their Killarney clones.
The furthest from that ideal have been some “Boutique whistles” (or “Barbie whistles”) that is gorgeous whistles crafted from exotic hardwoods and precious metals that just don’t play very well IMHO. They’re made for a different market, I believe.
Then with Low D Whistles (and nearby pitches ranging from around Mezzo F to the Bass whistles) you DO get what you pay for, in a specific price range.
There’s a place where the best alloy Low D Whistles sit, say between $300 and $400, the whistles by Goldie, Reviol, Lofgren, MK, Reyburn, and others. These all give a professional level of performance yet each is distinct in certain ways. (I’ve played them all and settled on the Goldie as the best for me.)
Below that and you just don’t get that same performance.
Oddly, above that $300-400 price point you don’t get that top level performance either, with the “Boutique” Low Whistles, once again of precious woods and metals but IMHO lacking in performance.
I’ve played several of these “Barbie” Low Whistles costing $700-900 and I wouldn’t pay a bent penny for any of them- they’re just not good enough.
Bottom line, a distinction should be made between “high performance whistles” and “high price whistles”. The term “high end whistles” is too vague IMHO.