[Shadbase]

Mans is going for the torch nerf technique!!
Realistically, I don't think that just nerfing it is really gonna do anything but make people go for the next best thing, and now that's the big moneymaker. (And dear lord if you heathens make Dev put back in the money tax for cutting seeds I will end you.)

But I think that in general, most items could be actually buffed to create worth for them, and then actually have some sort of sink you can funnel them into beyond asking for maps (which... not everyone needs a map made!!) or just selling them to a pawn shop; table scraps of money for your ACTUAL DIAMONDS, and things like that. At least then people can somewhat diversify their assets!
Or, hear me out... if possible, Dev could create a unique worth system for selling items to merchants. You could sell seeds, sure... but say you want to sell them in Geladyne? They could be worth more there - or even the fruits and vegetables they grow could be worth more! And then in Telegrad they're worth less than dirt.

But I still really love Damy's suggestion. It's highly unlikely we'd ever get it, sure, but god would it make non-combative jobs and skills actually kinda worth something? Not to mention, it's not like it'd HAVE to be 1:1 taxation that you have to pay as a player. Maybe more like making large donations to cities to fund projects done by the cities. Donating weapons you made to Duyuei to help with the defense on the wall, donating food to Geladyne that you were able to grow (because to be fair, growing food at max yield makes you an INSANE amount of excess food). You could even have those donations change little things around the city, as a visual queue of how things are going!! FUCK.