Storage Facility Evaluation - Help

[Kirby Davis]

I just had an opportunity come up that I wasn't looking for, and I don't fully know how to evaluate it. It's a 4 metal building storage facility with a total of 24 storage units that rent for $600/month each. Taxes are  $10,500/year and insurance is $3,450/year. Industrial type storage with 14 ft roll up doors on each unit. 

What other expenses need to be accounted for, and how what are recommended assumption rates (vacancy, capex, repairs, etc...)

Any guidance would be appreciated.