I have received several international orders. My experience has unique each time. For instance:
LV bag paid $3500 (ebay- back in 2003) - seller in Switzerland. Seller put a value of $1500. Shipped via their swisspost (express) ended up being delivered here in the USA by DHL. First time getting something I considered super expensive and from abroad, so was really nervous as I was told shipment would be held at Kennedy Airport until I get there in person. None of that happened. Got it delivered within three days and did not have to pay anything upfront. About two weeks after delivery, DHL sent me a customs invoice of approx $145.00.
Weird, on each of my USPS situations, did not have to pay customs:
Versace bag sent from Italy... sent from the Versace store (but I had ordered it from NYC) value at $2700 - received USPS Express Mail - no customs due on that
Prada bag and shoes ... shipped from Italy... value at $1400 - received USPS Express Mail - no customs on that either.
Chloe top - NWT - value $600 - ebay purchase - received via post office air mail - no customs
Just today, got several tagging guns and other supplies from China - value says $100 - came USPS air mail. Postman left at my mailbox - no customs due.
Didgeridoo sent from Australia value $800. came via DHL. Again no customs upfront, afterwards they invoiced me for approx $80.