There is a BP podcast about a lady in denver who built a portfolio of condos in Denver due to the high cost of entry (https://www.biggerpockets.com/renewsblog/2016/07/14/bp-podcast-183achieving-financial-independence-rental-properties-sarah-pritchett/) . 

The mobile homes and the lots are owned by the park.Gross monthly income is $2,070/monthOwner pays:-Trash is $64/ month-Water is $200/month-Tax is $25/monthTenants pay their own utilities, electricity and gasSelling because it has a lot of equity in it$84,000 with option of seller financingRent ranges from $275 through $575/monthOwner charges a lady who has lived on the park for 7 years the lowest rent of $275/monthCity sewage and city waterAny and all advice on this deal would be greatly appreciated.

What an intelligent young lady you are.

I have one young lady looking to get started wholesaling meeting me this week, who else is game?

I would definitely love to come to that meetup and meet you ladies @Canesha Edwards & @Rashida Sigmond.

Welcome ladies, It is so good to see so many females tapping into this great industry.

Are you a fan of those ladies?

The husband died, the lady is 92 yrs old and about to move in with her daughter.

If you were to apply income based valuation on 1 to 4 unit properties, you would likely get the wild swing that you have observed.Second, the formula of "Net Return" as you defined it (i.e never seen it used before) is essentially Cap Rate * 5 (i.e. using your assumption of 20% down).

So, I've talked with the lady.