Yeah this idea has been thrown about a lot in the past. We used to have player owned warps, but that backfired tremendously.

As Godsy said, nothing is stopping you making your own shop – find a town with lots of active people in it, and ask to set up a small shop there. You should make a healthy amount of money, while paying (hopefully) no money! Its in the interest of any town owner to attract players to open shops.

Before /warp shop was added, (one of) the main trading places was Aeos Island – the shops on there remained active and still attracted players well after warp shops was added. Its downfall was that many veteran players who owned shops there did not continue advertising their shop there. There is nothing stopping you from creating your own island, get loads of people to open shops, charge really low or no rent (to attract shops), and watch the money poor in. It’ll be up to you to keep your island’s shoppers safe.