In my opinion. the flip costs are grossly overestimated.
For say 1200 square feet:
Engineered hardwood floors installed by flipper in living areas: $2,000, or by contractor $3500. Add for bedrooms.
Completely new kitchen for smaller house $6,000 to $7,000, including cheap imported granite. Maybe $7-$8,000 if all work is subbed out
New half bath, assuming plumbing in place and permit obtained $2,000 to $3,000. Max $5,000 if subbed out.
Renovated small full bath $4,000 to $6,000, depending on materials and how much work is subbed out, maybe more if extensive plumbing needed.
Exterior paint for 1,200 sf home: $2,000, $2,500 max.
Rear sliding door $1,500 to $2,000 depending on door.
Full interior two-tone paint: $2,000
Rear deck $3,000 to $4,000, depending on size, more for the structure if there is a walk out basement and this is the first floor.
These are low end prices based on the flipper doing some of the work and having trade crews on tap. Also in LCOL area, not California or HCOL areas on the East Coast.