The house I bought had a strong pet odor, cat urine, and as part of the scope of work, I asked contractor to eliminate that odor, however house was repainted and work 99% complete, but odor came back.

They want the interior main floor repainted.  

This includes, repainting and patching some holes. 

Estimate is excess 1.5K for claiming half the walls and ceiling in the home need to be repainted, every door in the house needs to be cleaned, and other random items.

A drywall patch, mud and repaint will cost your, say, $300 regardless (I know the size of the hole matters, but your rent doesn't).  

They provide no real protection at all for the borrower/contractor relationship.So, if your house had some plumbing work that was done, and your contractor did not pull permits and they did not have the city inspect the work, then when you go to sell the house you will get caught and they will tell you that they need to open the walls to inspect the plumbing and then closing the walls and repainting are on you.The draw process is way too easy, I've learned that it is sooooo worth paying your personal inspector like $100 to do a deep inspection. 

On top of mechanical systems, roofs, exterior repaints, etc.  

If the previous tenants trash the place which many in the 3% areas will you will probably need to repaint, throw away a lot of trash, and clean and especially the painting can get expensive.In regards to renting rooms the maintenance might be lower but 1 thing about that is the amount of leasing to be done. 

I hate having to re-paint every few years.Similar to @Jaron Walling, I look for properties with slab/foundation problems.....

The entire interior was repainted a lighter modern color and LVP flooring was installed.