Hay Barn Ideas?

[jonbquick.com]

I built just a roof with 20' eves. I put 6" of recycled crushed concrete on the floor. I stack the bales 4 high around the perimeter and store my square bales on pallets in the interior. I will sell the square bales and the sell the round bales. The structure 30' X 30' X 20' only cost $1,800 including the concrete base. If filled with 4' X 4' round bales, it would hold 281 bales.

I am thinking of putting up a barn/shed for storing more of my hay. I use a krone baler making 4x4 bales. I can stack them 4 high. What are some thoughts on size and design for this type of barn. I would like to get 200-300 bales inside. Just wandering what others have done and how they did it. Currently using tarps but still have lots of waste. Seems to me the barn/shed will pay for itself after a few years by saving money on not having all the loss of hay.