i think it's better if user chooses from all themes (or from the ones which admin selects while adding an item)
![Smiley :)](http://smfshop.com/forum/Smileys/alive/smiley.gif)
lets say there're 3 themes and when user uses an item he/she can select which to use
i don't think it' reasonable to set different price for some themes
![Wink ;)](http://smfshop.com/forum/Smileys/alive/wink.gif)