How should I acquire this Self Storage Facility, and why?

I am in talks with an owner of a self storage facility and I am wondering which option is better to purchase it. A Master Lease with Option or Seller Financing and why?

Here are some details of property:

  • not listed, owner called me off direct mail campaign

  • 260 units in 5 buildings no climate control and 70% occupied (unverified)

  • owner has price in head of $1,350,000, probably from a broker

  • owner brought up seller financing in talks

  • I should receive financials this week from accountant

  • property is free and clear

  • agent for Penske truck rental - only one in 10 mile radius

  • paved, fenced, and has security system (unverified)

  • house/office in front of facility with 2 employees - 1 is live in manager

Thanks in advance for your input. Owner owns other property in town such as cell tower, vacant land and a sub shop and he has owned this property for 17 years and he is ready to retire, he is 71 years old.