You hire a work crew to clean, paint and repair the 4 units. 

This is essentially just paint at 1k per unit. i would want more than that but your inspection would tell you all you needed to know-in a 16 unit, they would be (should be) on separate electric meters, which would be billed to the tenants, not you.

Everything mentioned plus lead paint and asbestos.  

Roof is original (Shingle) $4k is as I expect to have to put in about $1k each unit in some shape as carpet, paint etc? 

If this is your first build, you need to think about level of finish on the Sheetrock, paint, lights, floors, underlayment, etc.

Then insulation, then drywall, then paint primer, then flooring, then cabinetry and interior doors, then base and case, then the balance of the finish work.

I can paint a house and install tile (started as a Handy Man 20+yrs ago) but I still hire that out, and pay well for it.

A buyer can't just decide not to and then go Rip Van Winkle without any consequences, it's a contract where they agreed to do certain things by certain dates or risk losing their EM, they are not window shopping for bananas. 

This article may help paint a better picture. http://renolandinc.com/reno-construction-update-ne...There is a lot of construction happening such as renovations to major roadways, including a north to south connector that recently opened and revitalization of downtown areas in both Reno and Sparks.

Current Situation: I purchased my first duplex back in June and have lived in it the last several months while I am giving the place a complete update (new flooring, paint, windows.. etc.).