Some sell after 3-7 years and some hold in perpetuity. 

Treat the lease as a perpetual annuity, and use the present value of all the payments to determine a proper cost.

It’s wrong and stereotypes shouldn’t keep good people from finding housing because of short sighted landlords

OR Do you think this is a good “starting point” and you always add to the $10K reserve in perpetuity, knowing the funds will likely eventually get used?

Life is too short - better to laugh this stuff off.However, once a tenant has shown they are going to be a perpetual pain in the butt, I send them on their way.Month to month baby.Lead poisoning is no joke. 

There is a significant expense in siting, engineering, and installation that most companies do not want to incur jumping from one pole to another.There has been a trend in the industry to buy out the landowners with a perpetual easement.

@Andrea Coulter I have been fortunate enough not to reach the point of eviction during this (apparently perpetual) ban on evictions in NYS.My attorney is John Keenan, and he is really on top of all of these changes coming down the pike. 

You don’t owe these tenants half price rent into perpetuity.

In your case it's probable that the seller is more sophisticated than your average FSBO situation from which that stereotype originates, but I would still want to run the asking price by some experienced local commercial RE brokers and get their opinions on the actual fair market value to make sure you're not overpaying.

If you're planning to hold in perpetuity, use year 10 as your "hypothetical" sale date.