What is the usual discount for lumber, cabinets, shingles, plumbing, and electrical?

The paint was chipping off of the wood siding,  the roof has a couple shingles missing, the fuse (not breaker) box had pieces of wire that had been poorly installed to add exterior outlets to the house, ugly old carpet, peeling linoleum, dated kitchen, etc.... then we find out the lot comes with 2 houses.

Property InformationPurchased for $68,000 (maybe worth $72K)1790 sqft duplex built in 1972Both units are 2 bed / 1 bathExterior: mostly brick veneer with a bit of vinyl sidingFlooring: tile in bathrooms, cheap laminate everywhere elseWalls: 1970's wood pannel throughout, but mostly tiled walls in bathroomRoof: shingle (not sure of the type), inspection said the roof is on the "second half of its life"Foundation: crawl-spaceInsurance Quote (if I lower the dwelling coverage)Calculated Rebuild Cost: $201,000Dwelling Coverage: $153,000 (I lowered it as much as possible)Personal Belongings: $2,500Other Structures: $15,300 (can't change)Personal Liability (each occurrence): $300,000Medical Payments to Others: $5,000Deductible: Other Covered Perils / Wind and Hail: $2,500 / $2,500Annual Premium: $472.55Insurance Quote (if I don't lower the dwelling coverage)Calculated Rebuild Cost: $201,000Dwelling Coverage: $201,000 (didn't lower it here)Personal Belongings: $2,500Other Structures: $15,300 (can't change)Personal Liability (each occurrence): $300,000Medical Payments to Others: $5,000Deductible: Other Covered Perils / Wind and Hail: $2,500 / $2,500Annual Premium: $587.36

Homes with EFIS (type of spray on siding) or Asbestos shingles or siding9.

He could buy enough shingles to get them at a discount, and he would save on having to deal with moving a crew around etc.

Long story short I removed the 2x4 roof rafters, the 6 layers of shingles, and framed a whole new roof in about two weeks. 

Been in commercial construction, operations, and management his whole life and moved back up there last year to hang his own shingle (and hunt, and fish, and boat, and snow mobile

Most loan types require that a shingle roof have at least 5 years left on it.

Look for deferred maintenance, like curling roof shingles, rotting window trim.

Hello, any leads on on a contractor that can give me a quote quickly on fixing a sagging roof and shingling a 1800 sqft single story house in Macomb Twp.?