Why is this on the market?

[Manzell Blakeley]

Hi - I'm just getting started in the journey and trying to wrap my head around the financing and cashflow elements of real estate investing. I've got a question about deals that look to easy to be profitable and wondering why, if it's such a great opportunity, is it on the market at all? 
I won't link to it, but the property I'm looking at is a 1909 brick building in St. Louis, MO of a kind typical to the area, going for $115,000. Two 1br/1ba units across 2,300 square feet, both currently leased and paying $550/mo each in rent. One of the units is on a 6-year lease, and it's advertised as turn-key. 

The drawback here obviously is the 6 year lease, meaning it will likely be a while before the tenants can be cleared and renovations can be made. But in the meantime, for your $23,000 down and ~$600/mo loan payments, you're getting a net cashflow of $500/mo, $6k/year on a $23k investment. That long lease is also guaranteed occupancy. You wouldn't be able to refinance but you'd net out your initial investment in 4 years. That seems like a great return for such a low risk. 

But given those same factors - why is it being sold? If it were already in your portfolio, wouldn't doing the minimum and just sitting on it be the play?

Thanks for your input!