I suggest looking at how IMVU deals with their skins. Instead of said-textures being on the server at all times, it loads the textures into a temp folder on the player's computer. These temp folders can be deleted by the user over time to clear out what they don't need anymore. When you come in contact with said-texture, it loads and saves onto the user's computer in the temp folder, not the server. If you haven't cleared your temp folders, you don't have to load them everytime you enter a portal because they are saved in the user's temp folder instead.
Then again, this would be hard on someone's computer loading a huge map such as the Plains, but if the plains were divided into small sections it could be possible. You would also need a file size limit on textures probably. Therefore reducing what Feral Heart would have to pay for servers.
That way Feral Heart could charge money for something worth spending money on and save server space.
