Hello and thanks for your maps. I'm enjoying them since FS 2019.
In the MP (modhub release) I've noticed that many (all?) products can be purchased from buying stations at a lower price than the average price at which you can sell it - with much "revenue" in easy and normal Economic Difficulties, but also some in Hard:
Examples: Mineral feed buy @900, sell @~3600/2100/1200, Diesel buy @1250 sell @ ~3800/2300/1280.
Obviously it's up to the player to "not cheat", but just wanted to leave a note (sorry if it has been already discussed but was not able to find references to it using English search terms)