Considering the size and amount of goods able to be stored, it is one of the best way to store goods. This can also account for it's larger price than other storage, costing even more than the Cargo Shed, whose price is 20 cash.
Super Grain Elevator seems to be the same size of, and have the same features as the Grain Elevator. The only difference is the color of the building itself. This does not account for the ladder, the silo next to it, the roof, or the shingles. Compared to the Grain Elevator's brown, the Super version is purple.