I think the reason is that your repairs tend to come from multiple categories: very cosmetic(carpet) to fairly substantial (new kitchen cabinets and appliances) to major systems (HVAC, roof, electrical) but rarely falls squarely into just one of those three categories.

So, if you are looking at high-end cabinets and stainless steel appliances then you have to find comps in that level of condition. if you are looking to basic rental quality upgrades then the comps should be in that range.

Being very picky about details, I notice the small things like when the property is advertised as newly rehabbed (new doors, appliances, cabinets etc) more often I see dings on the brand new door (I saw in one property in KC) or cabinet doors not aligning etc.

You've now sent me down a rabbit hole of kitchen cabinets.

(total about $3000) unit 2 needs some light kitchen reno - stove and cabinets redone, flooring.

Work include whole house painting (wall, door, trim, cabinet and some shelf), new vinyl plank flooring, and add a shower in bathroom.

The tenant put the fire out, but it has destroyed the stove and cabinets above it, and coated the entire house with smoke damage.

It's not in bad shape, needs new flooring throughout and the kitchen is empty (no cabinets or anything) and it's a condo in a very nice center so the only exterior work needed is some landscaping on the small patio. 

Added partition walls to create seperate bedroooms, pained cabinets, updated paint, added walk in shower, pantry room, basement kitchen.

This is a full rehab - HVAC to floors to Cabinet, etc.