People who build sheds (including home owners and woodworkers) know this for a fact - Sheds built out of wood are known to be more durable than those built from metal or vinyl.
I know professional builders whose sheds have lasted 10, 12, 16 years without much maintenance. While it's true that metal and vinyl sheds are cheaper than wood sheds, if you add the cost of maintenance & ownership over the long term, wood as a shed building material comes on top.
For those who would like to build their own summer or winter home sheds, check out 12,000 Shed Plans - Ready to Download