What is the commercial value of a product when exporting to an Amazon warehouse in another country?

For example, say you’re exporting goods from the US to an Amazon warehouse in Canada. You need to declare the commercial value of the shipment and you’ll have to pay corresponding duties.

You’re not actually selling the goods to Amazon, just sending it to their warehouse. So we’re a bit confused as to what the commercial value should be.

Would you list the full retail price, as in the price that the product will be listed at on the Amazon marketplace? Or would you list the price that you paid for the products, we’ll call that the wholesale price?