You can find most these items for normal prices on amazon too so this seems a bit like making a story where there may not be one.
My understanding is that there are generally 2 reasons for "outrageous" prices (in normal times).
1. Some vendors specialize in being the seller of last resort. They price their products high and wait out the market until they're the only game in town. This definitely happens with books, although I'd hope that with the advent of ebooks, this will be less viable.
2. Algorithmic pricing gone wrong. Sometimes multiple companies will set their prices on each other's current prices, resulting in gradual price drift.
(deactivating listings has an impact on future search visibility and other metrics)
This has happened with everything from bottles of tide, to ingame items in online games, it was no suprise it made it to amazon.
For example, Chinese garbage thermometers - ones that don't work and cost under a dollar to produce - flooded the marketplace when fever was announced as a common first symptom. Sellers took existing, somewhat well rated products like SD cards and used those listing to push their cheap garbage as $85 premium products. If you didn't look too far into it, it might even look legit.
Every related category had Chinese companies performing various scams. Frankly, until Amazon has a county filter it is going to continue trending towards being a bigger wish.com clone.
For example, Bounce hasn't made dryer bars for years. But you can find them on Amazon: https://www.amazon.com/Bounce-Dryer-Bar-3-83-Oz/dp/B003VYPKZ...
The store price was around $6. Currently listed on Amazon at $300. But it's not COVID-related. It's had that price for at least a year.
You need someone who can safely pass your money from paper to digital. The only people who can do this are folks with substantial paper money flows. Think cash-only restaurants. They report a modest growth in business, deposit your cash, and "buy" goods and services from you. But you can already fake this as a restaurant supply vendor.