The USPS reports that "arms & weapons" (presumably including knives, since "firearms" are a separate category) are in the prohibited category for shipping to the Netherlands:
http://pe.usps.com/text/Imm/mo_022.htm#ep1730218
If he insists on proceeding, he needs to send you cash, and accept 100% of the risk of confiscation.
In general, as others have noted, never declare a lower value, since that's your insurance limit; I always recommend Registered Mail with maximum appropriate insurance (international RM
usually includes
some insurance) for any item of significant value.
please do not assume,
knifes are no weapons, they are tools,
as a residence from California you should know better. your knife laws are more stick than ours
( i was given the advise staying in Cali to never tell the police i have a knife in my pocket , but a tool, it could be explained as concealed carry )
and shipping a knife to the Netherlands is perfectly ok , i received the most off my knifes in my 100+ collection knives from the US ,
as long as it is no double sided edge, push dagger, balysong or automatic, there is nothing to fear.
about the the value, yes i ask it to, but it will be on my risk !!! in know the rules and the risk i take.
i choose often for a fast delivery, and pay DHL / fedex for delivery. very secure and fast
we need to pay about 26% charge over incoming goods ,
you understand that i was not amused that one seller who was so handy to write on my 500 dollar knife ,
a value off 750 USD because "that was the replacement value off the knife"
and there is nothing we can do about this, you pay you get the parcel, you don't pay you will not receive it
as i already need to pay 50% tax over the money i earn,
i really not to keen on paying customs a very handsome fee for keeping my parcel at ransom
will leave my soap box now ;-)
gr, martin