I am working on a fantasy novel taking place in a fictional part of the world (containing three island nations) separated from the rest of the world. The economy of the three nations is separated from the rest of the world, and the reason is that they are three magical nations. The standard of living in these three nations is high, which contains free education (also higher education) and free healthcare. The biggest of the three nations' biggest export is fish and seafood and magical technology. Do you think these three nations would be able to survive and have such high standards of living without having slaves to work for them, when they are only exporting to two other nations? The first island has around 80 million people, the second has around 2 millions and the third has only around 1 million. Let's say the taxes are high. The reason why I am asking this is because I want my fictional countries to be realistic, even if they are magical.