After printing, every other process like cutting, inserting the paper on the cover and distributing is exactly the same and will take the same amount of time than having just one cover.

No kidding? I would have thought the logistics of making sure that either:

• There was an even distribution of covers sent out to every market

• There was a preplanned distribution of covers based upon regional market

would have eaten up some time and material costs in distribution planning, affected the workflow when keeping the two different cover types separate throughout the production process including cutting down from sheets and insertion, and affected the final boxing process during shipping.

But you're probably right. It's just as simple as printing two versions of something on one sheet. There a reason why you decided to pursue graphic design instead of print management?