we did not do the refinance to get the money out , the BRRR method. 

It may be possible to obtain a funding using this method.

If there aren't comps there I personally would value the property relative to its potential rental income using either the gross rent multiplier or cap rate method. 

On what to expect any learned methods that I could apply?

To give a little background, my aim is to focus mainly on BRRRR investing using what I've heard in the podcasts referred to as the "Stack" method: starting with SFH and working my way to small MFH and eventually Commercial MFH. 

This method becomes much much harder as you get older, ask anyone in the REI game over the age of 40...

What payment method do you all prefer when it comes to accepting rent?

Invest all cashLeverageBuy in syndicate Lets assume someone has say 100-500k in cash and is looking to invest in todays market in MF  Why would you pick one method over another and what would be your expected return etc. 

I now have 5 rental properties and they are all occupied and cash flowing nicely.I never used the BRRRR(an acronym that stands for “buy, rehab, rent, refinance, repeat.”) method until recently when I purchased my 4th rental due to the amount of equity I had from this property.

Depending on what type of underwriting method a Mortgage Broker found most suitable for your scenario + your credit score, you could get slightly lower interest rate although 6% is a good number to plug in to be conservative.