Snipe a half wine, rarest item in runescape. (There only is one half wine sold each 90 days so you'll have to be... let's say... a bit lucky to snipe one;D)
About the santas, I know there are merchants that have very large stocks. They basicly are raising them now, and they aint dumping. But who knows when they'll start dropping? I don't trust santa hats for now :O