Originally Posted by ralfp
Hotel shampoo bottle: $0.00
UK customs might argue about that.... $0.001 would be OK though!
Sounds like a joke, but I often had commercial shipments held up because alongside large quantities of high value goods, my supplier had added some free brochures. They had to be re-declared at a value - albeit nominal.
Notice that what you paid for something is not necessarily the same as its value for customs purposes. (Though one is often good evidence of the other.) Customs can even add the value of the shipping before arriving at the value of something for VAT/duty purposes. You can generally deduct recoverable foreign sales taxes from the value (whether or not you actually recover them).
In practice, nobody really worries about these minor details for non-commercial shipments and if you're below your limits then you're OK. US customs rules are probably different, but EU rules should be aligned.