Aesthetic upgrades for a price

It would seem to me that many games are moving to a model where one may spend real money in order to have access to a large assortment of purely aesthetic items with which they are able to create their own personal online identity.  In this way the actual game can be free, which works for me because I really couldn't care less what my avatar looks like so long that the game is fun.  That being said I do recognize the value of being able to customize, and also that some people are willing to pay for it.  And so some ideas that I have for this will be objects that people will be able to place on their personal or communal property.  This will mean things like plants, statues, wall paper, pictures, and many other items will need to be created.  I would love for players to be able to insert their own pictures and creations, but because of the possibility of inappropriate material that will most likely not happen.  The fact that people are going to be able to stack their own blocks will be difficult enough in the first place.  At any rate this is something I'm going to have to keep in mind, especially if this game is going to be able to stay afloat financially speaking.