3. Typecast bespoke wallpaper (starting at $241 per 10m roll, barnebygates.com). According to Lowe’s wallpaper calculator, the average 16 ft. x 16 ft. living room with two doors and two windows will take 31 rolls of wallpaper to cover. So yeah, you could give someone $7,471 worth of wallpaper… or you could give them one random roll and let them see how far it will go. Weird? Weird.