We're referring to an utility-based magic item economy as seen in d20 games. Little gold buys little power, lots of gold buys lots of power.
I don't see why you can't do that in 5e.
Simple and cheap magic consumables are still pretty useful. And unlike in 3e and 4e, things like tanglefoot bags don't cease to be useful because the monsters outlevel the static DCs.
At high levels, you can buy lots of cheap consumable Common and Uncommon items.
Look, I understand, you're not interested in a magic item economy. That's fine.
But you don't _get to claim_ 5e supports one, especially since you aren't interested yourself. What 5e supports is *not* having a magic item economy in the sense the game *used to support*.
You seem to be operating under the misconception that not having a magic item economy that YOU like equates with not having one at all.
I'm well aware you don't like how magic items were handled in 5e compared to 3e. But many more people seem just fine with how 1e & 2e handled magic items and complained about the 3e system (and 4e for that matter) and are very, very happy now with 5e.
I sympathize to some degree. But I also remember having to adapt how I thought about magic items when I switched to 3e. Magic was no longer special and no longer things you attached a story to: there was no longer special items created by elite orders or with unique histories because any spellcaster could just take a feat and crank a copy out.
5th Edition is not 3rd Edition. It was never going to be 3rd Edition and is never going to work like 3rd Edition. And trying to make it work exactly like an older it is not is just a recipe for frustration. While the design team had the goal of making 5e
feel like older editions, it was never going to do everything exactly like it had been done in previous editions. That was never really the plan.
Honestly, I could give a dead rat's ass about the economics of fully functioning magic item manufacturing industry.
I tolerated it in 3e, because removing the magic item treadmill was hard. And I actively tried to work around the magic item treadmill in Pathfinder with varying degrees success. (And it's retention is one of the reasons I'm not even touching Starfinder.)
I like my verisimilitude and logic between my game rules and game world. And I'm happy with the idea that magic isn't just something people make to sell. That there's not magical sweatshops where level 5 wizards churn out
cloaks of resistance and
+1 longswords.
While I like that magic items are made to use, and when they are bought and sold it is secondhand. The economy works just fine in that regard. People make magic at the base cost. Use it. Someone else sells it used for a tenth or half price. And then the vendor sells it to the next person for full base price, making their profit that way.
Don't think of magic item sales like buying new items but buying things from a pawn shop.