But after today's windows request, I'm starting to think that he might just be a perpetual complainer and will cost me money every single week as long as he lives in the unit.

What stereotypical needs will that age group look for ?

And the earth is still flat and there is no global warming and the solution to our energy crisis is Perpetual motion machines.You finally got it.

You sold your one property after 9 years...but if you just held it in perpetuity, you would have had a property at X value that was paid off by your tenants. 

What I’m saying is, there’s really no way to stereotype renters here. 

They want to limit my line of credit based on revenue, but they give me a perpetual 18 month interest free loan for a one time 2% transfer fee, for a huge amount of credit. 

Loc, by your description, this sounds like it is approaching a perpetuity - a constant, never ending stream of payments.The textbook definition of the "value" of a perpetuity is the cash flow, here $400 per month, divided by the appropriate discount factor.It is that discount factor that is tough to determine.You have 3 risks that I can identify.First, the ex may decide that the "meth life" or any other assorted lifestyles is better than paying this money forever.

Alternatively, you can buy used homes ($2k-$20k), rehab them for $1k-$5k, depending on the condition of the home, and rent them perpetually or slowly sell them via a rent credit program.  

I’ve got 3 tenants out of 54 that are not paying at all and about a dozen perpetually late payers. $10 per day penalty after a grace period from the 1st-7th.

I would imagine there would be an influx of perennial renters as the stereotypical user flocks to Colorado (maybe why I can’t come close to my criteria for Multi-fam properties so far on the MLS).