CowBoom offers the used, 1st-generation Apple iPad 32GB WiFi + 3G Tablet, model no. MC496LL/A, for $219.99 with free shipping. That’s tied with last week’s mention as the lowest total price we’ve ever seen for any 32GB 3G-equipped iPad. (It’s also $129 below the best deal we could find for a refurb elsewhere.) Sales tax…