The weird thing is, I don't see that much of a price difference between high-end "domestic" parmesan cheeses and the proper Parmigiano-Reggiano. The Saravecchio Parmesan (that's the Wisconsin domestic you're referring to, I assume) is about $17.99/lb, and the real, imported stuff is about $20/lb--even cheaper at places like Costco. So why not just get the real thing?
The big difference in cost is in the number of months of aging. Cheap Parmigiano-Reggiano might be 20-24 months old. It gets much better tasting, and more expensive, at 36 months, and better still (and more costly) at 40 months. We'd buy Parmigiano-Reggiano at Iper La Grande, a massive grocery store (imagine if a Wegmans and a Target merged) in northern Italy; there 40 month old would be about twice the price as 24 month old.
That some really odd pricing, there's no investment out there where you could purchase for x, let it sit for 16 months, and then sell for 2x. You'd think the manufacturers or some other entity would just be buying all the 24month to age another 16 months to double their money (less some warehouse / transport overhead).
This isn't just stacking palettes of crackers. Parmesan requires climate-controlled warehouses, and must be often tested, repositioned, and (yes) guarded. It's also a more risky investment.
Where are you buying your Wisconsin cheese for that much? I’m in the southeast and at Publix I can buy a wedge of Wisconsin Parmesan for half the price of the Italian Parmesan.
The price is about $7, but you'll notice it's only about 1/3 of a pound, so the per-pound price is $20-21. Which, again, tracks with what I've been saying. The only difference is you might be forced to buy a pound of the real stuff when you get a wedge of Parmigiano Reggiano, so there's a bigger upfront cost, but you'll definitely go through the stuff. It's delicious grated, it's delicious on its own, and it freezes well.
Side note, but Costco sells a full wheel of real-deal Parmigiano-Reggiano for what comes out to a little more than $13/lb. If you have friends or family who like cheese, splitting one up makes for a fun afternoon, and the hunks you get will last for a good long while in the fridge.