Help Estimating Rehab Costs?

[Justin Case]

Hi all,

Investing newbie here. I'm hoping to use the BRRRR method on run-down small multi-family properties in Connecticut. I found a duplex on the MLS that's in bad shape and am trying to estimate the rehab costs (pictures below). My back-of-the-napkin rehab estimate is as follows:

• Drywall: $20,000
• Flooring: $18,500
• Windows: $17,000
• Bathrooms: $16,000
• Roof: $12,000
• Siding: $10,000
• Paint: $9,000
• Cabinets: $8,500
• Appliances: $8,000
• HVAC: $7,000
• Doors: $5,000
• Counters: $4,000
• Contingency: $15,000
• Total: $150,000

Obviously, there are wayyy too many unknowns to accurately estimate rehab off of just a few pictures (e.g., what's the status of plumbing, electrical, any structural issues, etc.).  However, at this stage, I just want a high-level check on whether I might be in the ballpark.  Is there a reasonable chance I'm within 20% of the total rehab costs?  If I'm certainly way off-base, I'd rather not waste a contractor's time asking for a quote on a project that's most likely a non-starter. 

Any and all feedback would be greatly appreciated.  Thank you!