I've been watching purchase prices of self storage buildings. We call em mini storage down here. Recently I shopped a 792 unit complex on a main road. Asking price was 1.8 mil. Was claimed to generate $20,000 a month. I couldn't work the deal like I wanted so I didn't get far with it but that's for another day.
I don't have any minis but I want some.
Units are common here so compeition is heated. Someone will need to be available when it's conveinient for the customer to rent the units.
Consider fencing and gating the property. Security cameras and coded gates. Consider a few heated/cooled units. Route sales folks love these. Snow removal will be needed. Your
L39 has that covered.
The point is storage buidings make a lot of cash right quick. Structure it to pay for itself in 10 years. Sooner if possible.
Landlording isn't all peaches and cream. Expect to get calls nearly everyday. Be available to show the units and collect fees at odd times. Set up a mail box onsite and check it daily or set it up at the post office. The onsite box will need to be the big heavy box the post office uses.
Expect to lock a few non payers out and sell off their junk after holding it for the legal time in your state. Most consignment stores or flea markets will buy lots of stuff around here.
Join your local landlord association.
Visit landlord.com.
Mini storage owners have their own association but I don't have the url.
HTH