The Etsy shop Mythical Menagerie produces quill pens decorated with the colors and crests of the houses at Hogwarts. Each one has a painted and dyed pheasant feather. They're ideal for spell writing, especially since they're ballpoints and thus won't make a mess like dip pens.
Kellianne, the owner of the shop, is currently sold out. But she promises that she's making more. There should be plenty of demand!
-via Nerd Approved