Escalaras are incredible but very expensive. Appliance dolly with one up top and one on bottom works well. I always do a "1 - 2 - 3 - Step" for each step. The person on the top has the hardest work. I recently brought a Mortal Kombat 27" video game and a TSPP out of a guy's basement. After getting that monster game out, the TSPP felt as light as a feather. I need a lighter hobby.
Worst one I ever did was a Gottlieb Circus up stairs with a turn in them by myself. That was nuts!