I have heard those arguments far too many times and it fails to consider one thing.

The wizarding world is with a handful of superficial exceptions (Hogwarts Express, Knight Bus, Wireless sets) on a state of at best the 1890s, maybe even closer to the 1840s.
That includes being a preindustrial society where mass production is unheard of and profits from throwing out thousdands of identical products is unnecessary as no country HAS "thousands" of households needing such objects... and they keep using well made products from generations ago like the Black family Silver or many hand down wands... so even less market for new stuff.

HOW is such a society supposed to MAKE Billions in Gross Domestic Product to justify rents in the 100,000 GBP range for an average business building? Millionaires? Unheard of, annual incomes of 30,000 pounds/6,000 Galleons on average? Illusory.
The buying power seems to be oriented on a Guinee gold piece (5 pounds nominal) of the 19th century. Multiplying it to fake a buying power of a first world nation in 2020? BAD Mistake, narratively and economically.

The demand often comes from folks like the core at Caer Azkaban... lovely people to get to know, but a bit... fringe in their views on many aspects of life. Guncoddlers, goldworshippers, Preppers.
Not the best informed group to ask for economical advice and not willing to think themselves into a foreign world, so many stories insisting on throwing Harry in a muggle-ized american magical world show that too.
But it's not thought all through to the logical end. That society cannot exist as any closer ties to the muggle world and Kaiju like economy would turn them superfluous and swallow them whole. The quirkyness of JKRs creation started out as funny joke in her children's stories, but with all said and done... a world functioning like Caer Azkaban prefers would have stopped being a separate world after WW2.

And another angle...
Why would the goblins care about muggle market values? Are they even allowed to deal with the muggle world? They supposedly mine (or have mined a long time ago, the cavernous vault corridors being served by MINEcarts hint at that past) all the gold they need for new coinage, so they wouldn't need to buy for anything like the overblown muggle world prices. And with prices kept that low, neither could the wizards afford to go around and investing big... a very convenient revenge for the grudgekeeping blighters...

Well written and entertaining. well done.

Hermione and Ron's characters are so vastly different and antagonistic (on Ron's part) that Hermione would never allow the git to touch her. You have this so wrong.

Enjoyed reading it again.

Loved the story

Great story!

You did a fantastic job here!
Devious humor!
Loved it!
It's 3am, so you know that I appreciate this as I definitely need my beauty sleep!
Keep up the great work!

These prank tales are fantastic and hilarious! Thanks for writing this!

A relationship that relies solely on sex is very unhealthy and is doomed to fail.

Oh this was a great story! Enjoyed reading it.

i would torturehim he is scum evil greedy olddecripite old fossle

I absolutely loved the Quibbler article in this chapter, your Luna is endlessly endearing

"Hey Mum!" Neville Potter shouted. "Look! Two Aardvarks humping!"

Best ending ever. Can't possibly think of anything better than that

That was a lovely way to end this story! ... Kudos!

Merci
C'était génial