In that case, you would go into Seller Admin > Cart Shipping Settings, set your Domestic rate as 1.00 and your Int'l rate as 2.00, then set the Weight (rather than Cost) of your chosen container type as 2.00 and Submit to save changes. Then just configure your product with Shipping enabled, a product Weight of 0.00, packaged in that same container type you'd configured in Cart Shipping Settings, with a packing capacity of 3.