Give 'premium' themes to all

I'd like the ability to categorize themes as 'premium' - but still give them to all levels! This way, users get the sense that they're getting something 'extra' or 'special'.

Right now this is not possible. If I enable a theme as premium - I can't then give it to all levels. I might be able to trick it by actually creating a free level that costs $0 and making that the default.