Hello, I'm a new DM who's going to run Ghosts of Saltmarsh. I was looking through the DM's guide and saw the Helm of Transportation, which Captain Xendros in Saltmarsh can get you in 1d4 weeks for 2500 gp.

The Helm of Transportation is able to transport 1000 cubic feet of goods almost anywhere in the world 1d3 times per day, and as I thought about it I realized how revolutionary it would be for trade and transportation. Since it's only rare and only 2500 gp in the market, the king could have 10 or even as many as hundreds of them, and rent them out to merchants to transport their goods. Even a few would make a big difference. This would revolutionize transportation and the need for caravans and trading vessels, which could alter what kind of transportation technology exists and make the merchants more subservient to the king (unless individual merchants also owned these helmets.) It would also reduce the need for safe roads and could alter how law enforcement exists. Since distance doesn't matter, it could also change how societies interact and trade with one another, and geography and distance would mean little if societies can trade (or send troops over) instantaneously and over any distance, which would change everything from culture to what kind of political and economic systems exist. This could quickly result in every part of the world turning into a single global culture, much like we have today. All of this is speculation of course, but I'm just going through some possible implications for the existence of Helms of Transportation.

This is all from one magic item, not to mention 13th level wizards who can cast transportation. There are thousands of magic items and spells in D&D, and each magic item and spell that my players can get access to seems to create enormous implications for how the economy and political system of my world should function. Trying to reconcile the existence of magic and my world as I imagine it now seems like an impossible task that could take several years. What do I do?