We are paying about $80 a month at Raceway Storage in Freehold. We used to store at Pine Cone Resort in southern Freehold and paid about $550 a year.
Raceway is worth it to us because the trailer is on asphalt, access is controlled on our schedule (6 am-11 pm) and the owners are terrific to work with.
Pine Cone was our choice earlier because it was the only place we could find in the area at the time. It's cheap, but I only recommend it as a last resort. It's an open field and while it worked, I had a number of issues with the place.