That seems to be a common rate for a covered pull through in the NW, we just took a trailer to a place in Hendo, that is a larger spot and only $119. I stored a trailer in that Stormore place for years with zero issues.
Adam look at that same place, they have back in spots that are cheaper by a bit and are still covered, sometimes they let people store them in by the storage units uncovered, but I don't know how much or under what circumstances