I tried to buy a GPS USB stick at http://mightygps.com. I ordered and paid via Paypal the entire amount owed. The stick was 61$ and the postage was 19, 45$. I live in Europa and this company is based in Canada, so the charges sounded reasonable, even though the weight of the entire packet was only something like 200-300 grams. No extra charges was given on their website.
But after the order was given they returned and claimed an additional 63$ in postage to send the packet - making the postage a total of 83$! 1, 5 times the items actual worth! I refused to pay the additional charges and they reimbursed me a total of 65$, keeping 15$ in "admin" fees!
The total calculation was that I paid 15$ for nothing!!! Don't buy from this company - find somewhere else. There are plenty of offers around.