[@Spoopy Scary]

To add to [@Vilageidiotx] talked about the most accurate period-model you might have for an economic powerhouse is something like Venice. In which case you have as mentioned earlier: the merchants outpowering the nobles and becoming the institution themselves. As well, Venice cornered themselves a market in one of those non-universal resources and selling it out to people. This being the production of salt, which they may have enforced with their gold or their navy.

Venice though had an edge over the other Italian merchant Republics in that they also had at their disposal The Arsenal, which was the only facility capable of mass producing ships before the Industrial Revolution. And during their hay-day Venice had something like three Arsenals producing ships for themselves and clientele in the region who found it far cheaper to buy Venetian ships because they could produce them so fast and so cheaply over trying to build a navy themselves.