I am planning to come up with another online store within this year or so. Currently, I own one eCommerce store only. So, should I purchase a 5-sites license or single-site license? Will it be possible to upgrade later on?

DotStore has a smooth upgrade and downgrade process. You can opt for it at any time. For now, we would suggest you choose a single-site license. Once another store is live and operational for the customers, upgrade to the 5-sites license. In case your second online store takes more than a year to come into the business, you will save a significant amount of money. So, it is a cost-convenient and wise thought.