Most European army surplus sites will have them new, but shipping will be very expensive. It seems like none of them ship to North America using regular mail. They use private carriers.
http://www.asmc.de/en/Headwear/Caps
http://www.ranger-onlineshop.de/123191N-.ahtml
Flecktarn.co.uk is probably the cheapest solution. Their website claims to ship via Royal Mail, but both orders I made there last year were delivered to me by Fedex.