Maybe he has a thing about shoes. A shoe fetish? There's a reason those naked porn stars are usually wearing heals, right?
My H and I have this same discussion. Unfortunately it's about cars instead of shoes. My car suits me fine, it's reliable, PAID OFF, and no more than I need. He hates that his wife and child drive around in a 98 Ford Taurus with a small dent in the back left door and pealing paint on the bumper.
Maybe what he really wants is to have hot sex in a new Humvee.