From my experience having tons of things shipped from the States, it generally works that if it's marked as a gift, it won't be charged tax/duty up to a certain amount in value that it's declared for... if it's declared over a certain amount it will still get charged some. However it won't nearly be charged as much as if it were marked as merchandise.
UPS also charges much more in fees than does standard USPS (US Postal Service).
HTH.