What is your rehab limit for a multi-family rental?

[Brandon Rodriguez]

Hey BP community!

Currently looking at a 4-Unit building in southern California. This property has a NOI of roughly $450/month as is. I am in contract for 20k below asking and currently waiting on appraisal (which i know is a huge deciding factor). The building was built in 1920 and after first inspection, needs nearly everything updated. To condense the list to the important ones:

New electrical wiring/Panel

New Plumbing

Wooden window frames are falling apart (termite damage)

Wooden steps to back yard and 2nd floor units need to be replaced (termite damage)

Flat roof needs maintenance (leaks)

My Question is, where does an investor typically draw the line and say that there's too many repairs that need to be made?  What numbers am I missing in regards to cash on cash return?  Any help is always greatly appreciated.