what exactly are you selling? It can't hurt to put the items up here, and you can easily sell to people in the US - shipping isn't that expensive - it would run about $20 for a jacket, 6-10day shipping if you package it well
shipping skis internationally will be a royal bitch. Australiapost can't do anything over about 150cm i think, so you gotta use a courier (Fedex, UPS, DHL etc) = massssssssive cost. like a few hundred.