Radio Shack is a franchise, so what any individual store stocks is up to the local franchise operator.
While I don;t doubt that Home Depot and Lowe's don't stock these batteries today, as FiOS expands and demand increases they might.
Unfortunately handling these batteries is is a significant headache. If you want to sell them, you also have to be willing to take the dead ones, and arrange for proper disposal/recyling.
Most reasonably sized metropolitan areas have specialist battery stores along the lines of 'Batteries Plus' that do stock these batteries, as will many alarm supply companies.. That's the good news, the bad news is often the price. Ebay is generally a lot less expensive.
