Better curb appeal, carpet and paint, simple turn over... what would it take to increase 100 on each side and when are the leases up?

Newer appliances, fresh paint, landscaping? 

First of all, paint the siding, houses of that era were not typically white, it must have been re-sided at some point (probably when the original clapboards/shingles were rotting).

Will you pay yourself $15 for a can light installation where you have to remove, drill holes, locate attic studs, secure junction boxes, assemble and install lights, clean-up debris, and paint if needed?

If you buy a property that is distressed (REO, short sale, redemption, etc) or in bad or dated condition, you should be able to increase the value of the property by cleaning it up, paint, carpet, and other repairs.  

This is the property in question: https://goo.gl/qjnBJK The top maintenance items are: cleaning up after tenants move out (paint, carpet cleaning), monthly landscaping ($90), and a smattering of appliance repairs.  

When was the last time the walls were painted?

There were 4 or 5 units in need of repair and when I went to go see them I was expecting holes, mildew, dead cats, fire damage... saw dirty carpet, dirty appliances, minor drywall repairs, and a need for a fresh coat of paint. $3k-5k per "damaged" room.The managers I talked to both literally said, "I hate people."

The tenants before were living there for 10 years and upstairs unit for 5 years so I want replace some old windows, rip out the carpets and resurface the hard wood floors, and paint. 

I can do minor repairs such as replacing doors, tiles, and painting.