Deal or no Deal? Does the lowest rebuild cost win the deal?

Had estimates from $75,000.00, $80,000.00 and a couple Contractor's even said forget it, this will cost way over $100K. How is a new Investor to have confidence in estimating repairs when you get variations like these.

My offer to the Seller went as follows:

Property ARV = $240K     I had 3 Comps in the area. All details including St Ft of lvg space, lot size, # of beds, # of baths, assessed value, age of home, price per sq ft, zillow value, amenities and features, such as central air, garages, pools, fireplaces were compared. I tried to stick within a mile for my comps, but had a bit of trouble finding the best one that were under a mile. I averaged the Zillow Zestimates and Trulia Estimates of recently sold props to get averages for the area, however I may not be the best at adjusting. DIY kitchens can be $10K to $20K for homes in the $240k area. Feedback on this welcome.

Purchase price= $82.5K   (34.37% of ARV.)

Repairs = $90K  comes in at $45/Sq Ft  (37.50% of the ARV)  

Purchase price + Repairs represent 71.87% of the est ARV.

Seller said he had an offer of $110K, so I backed out. That number seem too high for me, thanks to all of the education that I have gotten. Although I have to say, I don't know how the Investor can offer that. Perhaps he is going to do a high end rehab? Or maybe my comps were not adjusted properly?  A check of records today shows NO SALE of this property yet, since Saturday. Maybe the Seller was embellishing a bit?

So if the new Investor buys this at $110K here is how it looks to me, even though I do not know if this is going to be a high end renovation or not, which could raise the projected ARV up.

NOTE: The neighborhood is mainly a rental area, and not the best for a Single Family home. NOTE: The seller has a sign due to theft please leave mail at this address.

If my ARV is correct at $240K

ARV = $240K  2,000 sq ft home.  Fair neighborhood at best. 3Bd, 2 ba rebuild assumed
Purchase Price = $110K

If he could rebuild this Gut/Rehab 2,000 sq ft property for $75K then see below

Total cash outlay for Investor if he sells it himself and IF he can rebuild for $75K

ARV = $240K
Purchase price of $110K + $75K in Repairs = $185K  (May take to spring to sell )
Profit = $55K 

If it takes to April to sell then 55K divided by 8 = $6,875.00 per month made but no interest, loan payments, r.e. commissions were factored in here.

* Does this represent a good deal to you Massachusetts Investor's at 77.08% if the ARV after buying, renovating and selling?

Above assumes that Closing Costs and holding costs were factored into the offer.