Yes, 20' x 3 rows = 54 barrels. Cost of the container, timber, hardware and paint comes in at $4K. Depreciated over 3 years, costs you $24 per year/per barrel to store them.
BTW, the taper is 9 degrees. The ends of the 4x4 in the middle are tied with 1/2" pipe sunk in 4" on each end. Allows you to pull them apart to remove the rails easily.