This dragged the process out even longer, making it both exhausting and expensive—I’ve already spent nearly $10,000 in legal fees.

Cash flow is after assuming 15% repair and capital expenses and 5% vacancy expenses. 

It’s usually best to open a separate business checking account so your rental income and expenses stay organized and away from personal funds.

A DSCR loan is going to require more down, have high fees at closing, a higher interest rate, a pre-payment penalty, and will require you to have cash reserves that you likely don't have at the moment.

He is putting in a spa (I think because it is 4 units this expense can be justified).  

One is the $10,000 repair expenses.

The capital required for Denver, and limited cash flow makes it a tough market to get your next one.

@Eric Coats, to answer your specific questions, estimating expenses are pretty simple. 

Agents are also advising you to look for expensive mistakes (like checking the sewer which could cost 5-40k) and using their network and contacts to find homes off market or FSBO.  

Do the math and you'll see it doesn't make sense.The best way to invest: increase earnings, reduce expenses, and save.