Contractors: Estimating a complete "gutting" and renovation

[Matthew Krickeberg]

Situation:

There is a home in my neighborhood that has been unoccupied for approx 7-8 years but has been maintained (landscaping, taxes paid, etc) minimally and so is not noticeably so. The next door neighbors are friends of ours and knew the previous occupant, the elderly mother of the son (lives out of state) who now owns the property and have been informal 'stewards' of the property since. They have been inside the property several times in the last few years and have noticed burst water pipes and accompanying damage, mold, pests, etc. 

My question is does the likelihood of a complete tear out (down to the studs, new wiring, plumbing, drywall, flooring, windows, appliances, etc) make the project easier to estimate for a GC? My thought is that this situation does away with the nuances of a typical rehab, like determining what can stay or be fixed versus what must be replaced or refinished. Would simply having the square footage, floorplan/bedroom and bathroom count be sufficient to get a reasonable estimate sight unseen? I have been in contact with the owner and believe I have a chance at acquiring the property from him, but I have no idea how much a rehab on this scale would cost and thus have no idea what a fair offer would be to effectively BRRRR this property. We all know how difficult it is to get a GC to show up for a newbie investor who doesn't own the property!

Thoughts? Experiences?