One of the results of fixing the bug that prevented towns from growing in wealth in regions with ports was that the GDP of a now wealthy port remained the same, while a very poor port was worth half as much. This mod is a companion to that mod, and increases port GDP by around 50% to compensate. You really want to get that other mod, otherwise any region with a port will never have a town increase in wealth, available here.
There are actually two versions of the mod. The basic version does just that, increasing port GDP to compensate for the effects of the (much needed) town wealth fix.
The second version also makes a few other adjustments to the same table. It eliminates the lower class industrialization happiness penalty for the wine estates, since in a absolute monarchy the tiny boost the upgrade provides wouldn't be worth -1 happiness for the lower class. Second, it increases the happiness bonus for the British Somerset House prestige capital building to +2, increases the repression bonus for the French prestige capital from +5 to +7, and finally it changes the industrialization unhappyness penalty for the steam drydock from -2 to the same -1 as its predecessor, hopefully to encourage the construction of more steam drydocks (and more AI first rates.)
Download links:
The plain version of the mod
The second version of the mod
Enjoy!