I use both Amazon Mexico and Amazon USA and always check items on I want on both sites. My experience has been that items on the Mexico site that show being shipped in from the states are more expensive than ordering from the US site. As an example, a pet urn was $35 dollars on the US site and the exact same product was $3500 pesos on the Mexico site. Also, some items on the US site are not always for delivery to Mexico but if you keep checking that can change.
I deliver to our home in Ajijic as we have 24 hours guards who sign for the packages. FYI - Amazon USA tells when your package is out for delivery and shows how many stops away it is from your home.