As noted, larger servers have significantly lower prices on average. On the flip side, you sell items much faster due to the demand. Honestly, I would focus more on other factors than market board prices. If you or your friends have any PvP aspirations, definitely stick to Aether servers. The pool of players is notably larger. As for the rest, if you fancy big populations and seeing large gatherings, I'd recommend Balmung. It's more casual minded, especially with the strong roleplay focus. So if you do want to dabble in raids later on, this may suit you. Gilgamesh favoures a more hardcore mindset, though that is somewhat debatable at times. Can't speak too much on other servers since I don't know them well. People talk about Sargatanas and your current server being decent.