Would you prefer an ongoing 20% ROI, while not expecting any increase in the value of your original outlay, or, would you settle for an ongoing 10% ROI, while counting on (uncertain) future appreciation that might compensate you for the other 10% that you could have been getting from day one?

Increase earnest money.

I take their financials into consideration when determining if I can find ways to reduce operating expenses and increase my bottom line.

They are currently paying $450 a month in rent and have not received an increase in their history. 

With rates moving higher, it is likely that your rate will increase in the future. 

Short increases the chances of a return call but being too vague decreasing the chances. 

Yeah focus on increasing your day job income, advancing in your career and keep an eye on the big picture.

Can you hire a helper or two to handle the actual mowing while you work on increasing the number of clientele you're serving.3.

I would tend to put heavier weight on MF rentals than a SFH lot, building a SFH is riskier than apartments mainly and it typically would increase your income. 

That said, I think most people would be surprised at how close they can get if they eliminate monthly payments and increase their monthly cash flow.