Siding and shingles don't look the greatest, it is a 1910 building so that is a con. 

If you have to tear off shingles, repair sheathing and perhaps rotted trusses/rafters, a simple re-shingle job could be thousands more.You mentioned slab work.

Was this to be a full replacement or the repair of a few shingles?

It also looks like it may have gone to a sherriff's sale in 2013 and got bought by Fannie Mae, who then sold it in 2015 to someone, who is presumably the current seller.Until I knew different, I would assume:- you need to replace the roof (shingles), and possibly the wood under the shingles too. 

If so, were permits pulled & were they installed by a professional5.Are any of the homes rented to students6.Is there a flat roof7.are there asbestos shingles - Heating systems- PlumbingSome companies will not write properties with systems that have not been updated The Year that the following were updated (either partially or fully) would be good to know:- Heating systems- Roof- Plumbing- electricalSome companies will not write properties with systems that have not been updated.

.#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.

Location - Spring, TX Built in 1977, 3/2, approx 1500 sqftContract Price - $120kLocked-in Mortgage Rate - 3.5%Total Monthly Rent - $1450- Comes with Section 8 Tenant (Mom & 3 kids)- Buyer pays title insurance- Big items to account for after inspection: Tree too close to the house, needs to be cut downOne side of the garage door opener has no outlet to plug into (there are a total of 2 single garage doors)Kitchen sink drain pipes are "amateurishly" doneRusting of the evaporator coil in the attic (20 yrs old)Attic lines don't have enough insulationOne bathroom toilet is cracking and needs to be securedRoof is missing guttersRoof shingles vs flashing wasn't done 100% correct, needs more spaceThe buyer agreed to a $500 closing cost credit.

For instance, re-shingling a roof over an existing roof, he feels there more flexibility to classify that as a repair, because it's not a 100% brand new roof. 

Since we lived in it 2 of the last 5 years, we would not have to pay around $25,000 of Capital Gains Tax.I have been making repairs to it, new shingles were $8,500.

You may find that the brokerages with the high commission split don't offer as much by way of coaching and training but is more like hang your shingle here and good luck.