I've been to the US last September (I live in Denmark): buying my first DSLR (EOS 1100D), a MacBook Air, plenty of other stuff= 3500 EUR; paying 0 EUR at the customs after throwing away all the packaging and receipts= priceless!
Notice that I had with me also a MacBook Pro, worth about 2500 EUR, which I bought in the US a couple of years earlier, again without paying customs to bring it to Denmark.
I read so many silly statements above. I lived in the US for five years, traveled back and forth 12 times, and never paid a dime to customs. Of course, again, things in your luggage have to look like personal items. If one is so naive that packs everything including shopping bags and receipts, I think one deserves to pay for it.
Btw, here in Denmark one pays 20 EUR handling fee +25% VAT on camera equipment shipped from outside the EU. I tried to make the customs believe that I had a girlfriend in Hong Kong, but they didn't believe me.