@Johnathan Williams, the most value is added with roof repairs, mold remediation and water penetration causing mold, flooring and siding repair that are CLEARLY rotten and would CLEARLY depress the price if sold "as is," complete rewiring if the electrical is old enough, and hvac repair but not upgrade.

If you can do some upgrading maybe you can significantly increase the rents upon tenant changeover?  

Cash flow versus investment increases is a function of watching pennies, adding value, upgrading the inside and the outside of a unit in order to achieve higher rentals year after year.

But I also see a lot of people still waiting to buy even their first home or waiting to upgrade.

@Keenan Patton, what's the $50k in upgrades getting you?

I want to continue obtaining multi families until I am eventually able to upgrade to an apartment building.

So here is my story, my first bad experience as a landlord.Bought a duplex, moved in to the 2nd unit, did a lot of upgrade in the house to rent out the 1st unit to a family.

If your plan is to have the current owner repair the foundation along with other upgrades, one suggestion is to complete the renovations during the escrow process and only close if the repairs are executed as drafted in the contract. 

Better yet, find internal motivation (inspiration) through self-reflection, consciousness hacking and success visualization.Make mistakes and fail quickly.

Upgraded electrical using an electrician and general updating.