You need to determine what the repair costs will be and what the ARV will be (not what the seller tells you it is). 

Quote from @James Bolt: So i bought a duplex (4/2 & 4/1 1/2) with a built-in contractor that wants to bring it back to life: Alot of cosmetic repairs.

The resulting damage required repairs costing over $3,500.Sewer Line Replacement: During the shower remodel, broken tile pieces and debris from the GC’s work were found clogging the sewer line, necessitating a complete replacement at a cost of over $3,900.Additional Issues: Poor workmanship also led to defective toilet installation and a leaking kitchen sink, further increasing repair expenses.In total, the GC’s negligence has cost me over $10,000 in repairs and corrective work, in addition to the original rehabilitation costs.

You can always negotiate down on the repairs if you want.

I’d recommend asking about the property's overall condition, especially the roof, plumbing, and electrical those can be big-ticket repairs if something’s off.

Hey Eimen,In my opinion, the best way to approach this would be to get a rough estimate of the repair costs.

Wait until an HVAC or roof fully goes, usually looking at $5k single item repair cost.

So far it looks like a positive cashflow deal.Taxes $1700/ yearI was figuring about $1500 for insurance.5% for vacancy, 5% for repairs 10% Cap Ex

Here, the most common mistakes I see DIY BRRR investors make are underestimating ARV and repairs.  

It’s helped owners cut down on turnover, repairs, and vacancy costs."