Just to add to the ideas for temporary "Gold Rushes"
Maybe have a system or cluster of systems have special RES that spawn high % of all the high value mining commodities but only for a short amount of time, say 2 weeks.
There could even selection of new commodities that only appear in these rush.
So there is a Galnet article saying a mineral rich part of a Ring has been discovered, this could be in inhabitable space or nearby in the wilds
And a New RES or GES (Gemstone Extraction Site?) type is spawned in those systems only that one can find asteroids with Painite, Jadeite, Moissanite , Opal , Spessartine, Rhodolite , Corundum & Grossular, thought not all at once
Give these very high value at Service and Tourism Economies, and more so when in Boom.
Maybe a selection of up to three of them, and different group would be selected each time, and tie it into changing Fashion
So the GalNet article could talk about how jeweler made of Rhodolite is all the rage in Alioth High Society this month, and so Miners are rushing to PLEIADES SECTOR HR-W D1-57* where Rhodolite rich asteroids can be found, and sold for high prices at Service and Tourism Economies star ports
Then next month it might be about how in a Popular Dreamware Medieval Fantasy Soap Opera Character was seen wearing a Tiara with Corundum & Opal and so licenced reproductions are in High demand in Service and Tourism Economies star ports, and mining for the gemstones have double in the rings of WISE 0350-5658*
Etc Etc.
This giving in game information of what to mine, where to look and where to sell
*systems picked at random for example and may not contain any mining locations