Mr. Scanlan tells the Bunkers that they have to pay for shipping and installation to avoid the gift tax. The gift tax is paid by the giver, not the recipient. (Note: Scanlon most likely had Archie sized-up as someone who would believe that the recipient would pay the tax).
Mike comments to Archie about signing a contract to have aluminum siding installed on a "brick house". Just looking at the front porch, throughout the series, it's clearly not brick.