As a SFR investor for over 15 years I have been wrestling with this question in the past, because it feels like you should upgrade to "bigger".I know for sure that I would not enjoy the ownership experience that comes with a small 4F, because in Milwaukee that typically also means lower income tenants. 

Personally I wouldn't feel comfortable trying to wholesale a relatives $1M home knowing that I am breaking the law if I cross over into doing anything that can be considered representing them in the transaction, and knowing it will only be marketed to people who buy properties wholesale (typically investors who don't want to pay retail prices), instead of the majority of retail buyers active in the market who are typcially willing to pay more. 

It has to be something the individual wants, and let's face it, that isn't your typical BP investor.

Quote from @Ogonna Odo:  Small ones will not, they typically like cash or checks.

@Polat CaglayanI've never seen a formula but here is a general rule of thumb for multifamily:The class of an apartment refers to the quality of the building, which can be determined by a number of factors, including age, location, and condition: Class A: These are the highest quality apartments, typically built within the last 15 years.

Do you know how much the typical bills have been in the past?

It needs to be replaced with a typical bedroom doorknob/lock so a locksmith would not be needed in the future. 

There are also 'mezz' lenders (typically for larger transactions) who will cover up to 90% CLTV and require you to bring the remaining equity to the deal, and additionally there is Gap Funding in the form of unsecured personal debt.The latter can potentially be the most expensive option, but allows for true 100% financing as there are no restrictions for how to use these funds, as they are unsecured, and generally obtained through personal credit, income etc (since there is no collateral for obtaining these funds).

Holding company typically if you have multiple companies like a property manager, own property and other businesses. you will end up spending more per year on accounting and state stuff than what you make on your rentals. 

While I don’t typically work with real estate agents to find deals, I do collaborate with other professionals throughout the process.