Yeah its worth it I've bought valves, crane roller rockers, ARP studs, guidplates, crane valve springs all for at least 40-50% off Aussie prises. Bought over ebay through a reputable guy.
He shipped in small packages that cost $20 Aus I received in 7 days, no customs, he also marked "Warranty Replacement" on the parcels with a $30 value. If you go one large parcel you'll have to pay tax if you a small parcel with Warrenty replacement no tax and no customs.
With the US dollar at .75 - .80 cents now is the time be buying from the US