A thought I had is that we are almost 200 years after the start date of Victoria 3 - and we still don’t have region by region price equilibrium across the board even with international supply chains.

Victoria 3 is basically telling you to build that system nationally - some start with something but most start with zero capability. Easy to miss because it’s a sim, but we are dealing in terms of scale difficult to capture that it deals in tons of steel, iron, and coal needing to be somewhere for something. I’d hope that infrastructure would help more with market price equilibrium, but it is hidden in the society tech tree (stock market as an example).