Now each month the rents clear and then I have the funds sitting in my account for the rest of the month and ready for the payment the following month.

When both units are rented out the property should net cash flow around $1,000 a month.

  $600 X 12 months = $7200. 

Short answer:  a sewer scope is ALWAYS worth it.A couple hundred bucks to potentially save yourself tens of thousands, and weeks or months of lost time and vacancy?

They have great programs out there for you, even pay some of your vendor bills based on your transaction amounts monthly.  

A couple months ago, they listed it for $80K before dropping the price down to 70K and then $65K.

@Juan Zamora Typical DSCR loans use long term rental leases or appraised market rents to qualifySTR loans use in place (if ST rented for 12 months) OR market data from Airdna, local STR operators and the like, to qualify the income. 

She's been renting it for $2,800/month and the condo has a $600 monthly HOA.I want to offer her $350,000 for the condo (its a fair price for it), 5% down payment ($17,500) and pay her monthly $2,000 for 3 years, after which I would refinance and pay her out.

I currently have a tenant in place who just renewed a 12 month lease.

The second tenant stopped paying and it took me 4 months to get them evicted and more turnaround cost.