I ask for what the ages are and relationships.  

I 100% understand that state, county within state, building type, age, depth of coverage, etc., etc., etc. is going to make every property unique, but it would be great to come up with a rough rule of thumb that will allow a conservative estimate.

TschidaSome questions you should ask yourself are, do you really want to own property in Indiana at the age of 65?

@Alex ClarkCongrats for accumulating $100K to invest at the age of 21.

Current age 40.

Does anyone have any negative/positive personal experiences with buying properties of this age

I'm not sure I would end up selling - I actually think they become more beneficial as you age.

There is, however, if properly managed, a distinction between building reserves and funding depreciation.Oh, and when you sell the property, unused reserves become ordinary income, and you pay the hit. 

Some may pay taxes under someone else's social security number which may boost our aging population's social security coffers.

I want to say you are doing an amazing job at your age!