The kingdom has always been an interesting little spot which I found enjoyable enough to maintain and collect from.
Once I discovered that with appropriate amounts of coffer input and adequate care taken to maintain reputation, on the right output setting I could make money, I was significantly more interested.
I am not sure exactly how much money I made over the years from this D&D but it can't be all too much given the amount I've poured into the coffers.
Anyway I'd propose that the kingdom supplies should be something more akin to protean skilling supplies, providing the ability to train the related skills and perhaps even make the related products (similar to protean planks) but not be a big resource injector into the economy. For the same reason that bots are a scourge to the game's economy I also dislike and disagree with the Kingdom being a plantation slave of the elite.
As a possible alternative to collecting skilling supplies, maybe there could be an "investment" option with the Kingdom coffers, where the output could be straight GP with some possible variable rates like an actual investment would be. I dunno. I am not really all that attached to the Kingdom being a money-maker, but if it was something Jagex thought was a good thing, then sure, something like this could work. Opportunity cost of giving up the skilling supplies.
Anyway yeah that's my two cents.
*imagines running the kingdom for three months and collecting 20 elder logs*
18-Jan-2019 18:36:44