Suggestion, Mesanna....
Recently on Great Lakes we had a wedding, wherein the bride had a custom, EM-made wedding dress....That had a timer on it.
So it could not possibly become a rare to sell.
Leaving aside the question about how I personally feel about something that amounts to custom rares, it does create a perception problem. And that's almost as bad as a real problem.
So I'd suggest that you get around the problem the way the GL EMs did....Put a timer on the item. You can support player events and not create a new rare, both at the same time.
-Galen's player