For reference, it would be a roughly $300k property that would generate ~$2,250 in gross monthly rent.

There are many other investors who would buy properties that would break even with one unit not generating income all day long in that area, and they'd offer cash and more than you appear to currently willing to offer.

My goal is to generate another stream of income for retirement and am not interested in amassing a multi-million dollar real estate empire.

It’s an active trade generative ordinary income because one is selling inventory, in this case real estate.

Later on, you can start playing with off-market deal generation via wholesalers or actually contacting homeowners directly. 

To decided if the property would generate cash flow. 

@Phillip RosinA vent is required because water heaters generate a ton of heat.

The property tax definitely plays a huge part in making rental properties more difficult to generate cash flow.

I guess it would be generating cash flow?

Tony Nitti, a well-respected Forbes tax analyst, formulated it best: "As a Tax Court judge once said of the issue, “If a client asks you if the sale of a piece of property will generate ordinary income or capital gain, tell them you don’t know.