Due to the price of materials and the relative difficulty of installation, wrought iron fences are usually more expensive than aluminum fences—but not by much.
For those of us who want sheds that are very small, such as five square feet or less, then it will not really be necessary to add any sort of roof onto it. This is because you will only need to spend money on the framing itself and this is something that you can do yourself. Therefore, if you already have a strong foundation such as concrete then it will make sense to install a concrete wall as the main part of your shed.