Originally Posted by Koyote

I guess it's easier to see conspiracies than it is to apply logic and to acquire facts.

You can go right on Amazon and buy 50 of those 12g unthreaded cartridges for $29, which is $.58 each -- only slightly higher than the price ($.50 each) the OP claimed to have paid a few years ago. The slight price increase is unsurprising, given that inflation is ever-present. And since the OP apparently bought the inflator, I won't provide links to the many available options.

Inflators that accept 12g unthreaded carts are unpopular precisely because 12g carts are unpopular -- they don't provide enough inflation for the tires that more and more people are running. Also, unthreaded inflators are generally less popular than threaded adaptors. Any threaded inflator will accept any threaded CO2 cartridge of any size.

tl;dr: threaded carts (and their inflators) and larger (>12g) CO2 cartridges are more popular, and that's why they are more widely available...Because capitalism.

PS: A "Corvette tax" is a hoot. Corvettes are high performance vehicles, which means that the parts are built to be lighter, stronger, more resistant to heat and other forces, etc etc etc. That's why a Corvette costs more than most cars, and it's why the parts cost more. Sheesh. Can't believe I have to explain this. Do you really think that, e.g., the wide speed-rated tires for a Corvette have the same manufacturing cost as the little low-performance tires that go on a Corolla?

PPS: Get a mini-pump.