First duplex, concerning inspection report. Advice welcomed!

[Daniel Villagra]

Morning BP community, 

I have an offer accepted on a duplex (built in 1905, $150k, $700/mo cashflow, 2 - 2nd/1bath, total of 2300 sq. ft. and rented out), and the inspection report has left me on the fence. Do I ask for repairs/price reduction OR do I walk? 

Most concerning items: 

- Roof is 20-25 years old and needs replacing. 

- Has knob & tube in the 2nd/3rd floor. 

- Exposed cast iron sewer line in the basement is showing a small crack/leakage (I can replace) but I'm concerned about the corroding under the foundation to road. 

I projected 5k for each unit to modernize/rehab and wouldn't be willing to accommodate additional expenses. Ideally the seller reduces/fixes, but would you experienced investors still move forward on the deal? If there is any valuable info I have left out that'd help you give me better advice, please let me know and i'll throw in the thread.

Thanks everyone!!