I pay 150 a month for a pull through covered storage. They allow you to hook up the 20A electrical with no charge ( I don't though). They have a wash station and dump station available for use by all clients with no charge. Coded gate access with the manager living on site.
This facility was the only one I could locate in this area with covered storage, so supply and demand effect the cost. I used to store it at an outside unsecured area at a local rv park for about 1/3 of the cost. After an attemp break-in, I moved it to the secure location.