But to be successful and profitable, takes some distinct characteristics:1.

They are starting to age out.5.  

Ranking in order though...1) Prices will drop - 10-20% because the job market is getting tougher2) Salaries will increase - 3-4% per year to keep up with inflation3) Interest rates will drop - 100-150bps as people worry less about inflation4) Unfortunately, the dream of a house with a white picket fence will be out of reach for many, especially before the age of 40.

I've tried a couple - truepeoplesearch, white-ages, property radar, leadsherpa, batch leads...Some services are better than others, but it is a numbers game and you also can cross check between different platforms.

The condo will limit the rental options to age restrictions. 

Your referencing effective age vs chronological age. 

I wish I got started when I was your age.

In Reno and metro areas, insurance companies primarily focus on roofs, the age of the building, wiring updates, and water pipes, as mentioned @Cameron Moore.

However if you have enough reserves, 6mo or greater then I'd say chance it but a couple of missed payments from the tenants and you have to foot the payments out of your own pocket.I'm all for taking risks but I think you really need to evaluate the age of the major systems so you don't get hit with a bunch of cap ex all at once as well as your reserves. 

@Polat CaglayanI've never seen a formula but here is a general rule of thumb for multifamily:The class of an apartment refers to the quality of the building, which can be determined by a number of factors, including age, location, and condition: Class A: These are the highest quality apartments, typically built within the last 15 years.