Its one of the disadvantage of being outside the EU! We had similar issue when MIL sent parcels to OH back in Ireland. Don't know if they include postage in the calculation here, but they do in Ireland, so once you reach the threshold for tax/duties, the cost of postage is added, before they apply the duties (eg contents = €100, postage = €20, vat/duties calculated on total of €120) and then there could be a couriers admin fee too if you use DHL or the like. On one occassion we ended up paying about €70 in taxes/duties for a pair of jeans that MIL sent over, wasn't very happy to get that gift!
I have bought a few things online here, but haven't been charged for duties/taxes, yet! Do wonder what happens if I have to send something back - can I get the duties refunded, I wonder? I assume not.
As has already been mentioned, I would query how the charge was calculated as it does sound high for the value of items received.