The builder should have that info.I worry more about how those are installed on the roof and if it changes the integrity of the roofing shingles.

That's like $10.5K (part will go to your broker where you're "hanging your shingle".)Once your investor has fixed the property, guess what, they're going to need an agent to sell the property which is now worth $250K.Who are they going to list it with if they want you to keep getting deals?

The (green colored) siding is made up of almost like asphalt shingles.

I've also seen the brick removed directly under the window & replaced with shingle, but that looks a bit wierd.

Asking the listing agent about repairs probably wouldn't get you very far as real estate agents are not contractors and wouldn't be able to tell you about galvanized plumbing or shake-shingle roofing.

I went to Owens Corning to talk about the 30-year shingles that are falling apart, streaking, and separating after 8 years.  

However the manufacturer of the shingle CLEARY states in their literature that a Double Dipped Galvanized nail MUST be used.

Caulking with a quality roof sealer like Vulkem is inexpensive.Rafter sag - this caused the roof to sag in certain areas, which my inspector said is typical for older homes that have no collar ties installed.How many layers of shingles?

 @Erik Shingle: Im still going to be working in New Jersey where I currently reside right now, so a neighborhood close to the highway would be a nice one. 

.#3 Contact Local Contractors for Labor PricingCall local Subcontractors and get budget pricing for common repairs on your typical rehab project.For example, call a roofer and ask what their average cost per Square of Architectural Asphalt Shingle Roofing would be on a 1,500 sf house, with a 6/12 pitch.Note: Some contractors will be reluctant to share pricing without seeing the property, but tell them you are just looking for a rough budget number you can use on future projects.#4 Compile Your Prices into a Spreadsheet or Estimating SoftwareOnce you start to get a better understanding of Labor and Material costs you will want to store this data into a spreadsheet or software that you can use to help you streamline the estimating process.The Book on Estimating Rehab Costs comes with a spreadsheet that you can use to help you populate your own database of labor pricing and material pricing.