Various MMOs have gone from being subs-based to F2P (with the caveat that some content can only be purchased), however they - esp. Lineage II - have been subs-based for a very long time. Do you charge a lot for the initial purchase or make it so that people need to make the occasional purchase? I wish we could go back to the days of Phantasy Star Online where you buy the game for a reasonable price and just pay for your internet access (which was free for us in Europe if we entered our own ISP settings; pre-DreamKey 3.0 we had to use the US-version of the setup disc ). The best of both worlds.