Or simply to use REI to supplement your income.On this particular deal though, that all may not matter though.If you bought it for 52k and it needs 5 to 7k, then you're going to be all in at 60k.If it will sell for 80k, there's not much room there for any real profit - even less so if you're going to split it.  

My goal is to build my portfolio with as many positive cash flowing properties as I can to supplement my pension.

Its a nice way to supplement your housing costs.

An extra $550 admittedly won't mean as much to me 15 years from now as it would today, but it will certainly be a more meaningful kicker to supplement the cash flow already coming in from increased rents over the years.Call me pliable, but I think I'm tilting back to 15 again : )

When my rental income is filed on form 1040, it's attached with Schedule E:  Supplemental Income and Loss. 

I'm trying to learn about the world of real estate investing through books and am hoping a degree in finance can supplement this "career". 

To avoid to pay for the supplemental tax?

As @Ronan M indicated they are common for years in other parts of world (I see many in Europe where the heating is often primary radiators (no ducting) with Splits providing supplemental heat and AC. 

I was lucky and found a brokerage that was started by a couple who were investors first then the wife got her license as a way to supplement their investing business. 

My goal is to own buy and hold properties in order to create a passive income to supplement my income.