D&D 5E How were the "Sane Magic Item Prices" arrived at?

[Starfox]

The reason I have magic items for sale is that my version of the World of Greyhawk is the opposite of a points of light setting. The trade is booming, magic is increasing both in raw power (available mana), the number of practitioners, and in the styles of magic available. Yes, there are artifacts made during previous periods of peak magic that are still hard to replicate, but having magic items be few and far between would not fit my worldbuilding efforts. By the same token, if there is a way to create a permanent flight item for 1,000 gp and another for 15,000 gp, the later would have to be a lot better or it would just cease to be made and previously made ones would fall in price.

Edit: Magi is developing in that is becoming more common, but not more powerful. Mages in the past were few, but powerful. Mages today are common and growing more common, but each do not have the same power as those in the past.

[off-topic] For a fun aside, this seems to be the same as what happens in Star Wars, except the timeline is revered. In the early films, force users are a dime a dozen, but weak. In the laster films, on a few force users exist, down to less than half a dozen, but they can telekinetically move starships. [/off topic]

 

[Paul Farquhar]

real life prices can be pretty nonsensical

This. The idea of "sane" prices is pretty fantastical.

Real world example: Tulip mania - Wikipedia

 

[MichaelSomething]

One way to arrive at a magic pricing system is to create a magic item economy in a living campaign world with multiple groups. After a few years of buying, selling, and trading magic items among real life people, we should have a good idea how to price them.