For several reasons which include trade, larp, collection and showing off, it would be interesting if the game had a few things that are extremely rare.
Wild flowers, for example: we have blood stern, edelweiĆ, bluebells, chamomile and wintergreen, each being increasingly rarer to find.
What I'm suggesting is that a few more are added to that list, to the point that even in late worlds there's always something that's difficult to find, regardless of hq industry and 5 digit stats. This could apply to other stuff too, not only flowers.