Slitherine

A Trade Center increases the regions Acumen by +5 and a Pleasure District increases it by +3. I use a lot of money, manpower and metal producing structures in my regions. So trade items that give these structures useful or bonus items make a lot of trades. Here, little Sinai is making 612 money from iron and copper. I've had regions make a lot of money just from salt. An inland region needs better roads to get their trade items out. Harbors also increase trade range.

Good luck!

You appear to be making making 340% of the base value of that iron trade in a region with, what, a +22% local commerce modifier. Also, you have 146k money in the treasury, with 4.8k income well beyond the point where stockpiling money is supposed to hit diminishing returns. So... What I'm getting from this is that Stoas are still insanely overpowered, despite their previous nerf.

It's hard to make out, but it's only 242% in Sinai. I have an overall of 220%.

Stoa issue is not appearing in the income. From time to time you'll get it by a kind of inflation event (abstracted, the game won't adjust price) that will cost you loads upon loads of gold. Greed will hit you back at some point ...

I got that message about my coinage devaluing for several turns. However, I was always making more money in total than I ever lost. Eventually the event stopped and I'm still getting +225% to commerce.