One of my wife's uncles was in charge of one of the properties which is zoned for commercial/residential, it is a 1708 Sqf office space/small warehouse on .36 acre lot.Which with some research it can be split into 2 lots.He let the property go to the dump, needs a new metal roof, and gutted, replace plumbing/bathroom, replace electrical etc...Now my wife’s Aunt is in charge of the estate and she was the one who approached me.She said they will "sell" me the property for $30K (estimates from Real estate agent say property is worth $43-$53K in current condition) Which then I could clean the property up and try to resell with the improvements.Now if I did replace the roof make the inside look nice and clean the overgrown landscaping I was told (real estate agent) it could get about $60K, but there are back taxes and liens on the property as well.Plus closing cost for when I sell it, I have run the numbers and it seems that I would MAYBE make $3000-$9000 conservatively.But I am real concerned over the fact that it is used as an office/commercial, and wouldn't this limit buyers?

A reasonable estimate is $270k on the current condition.

Or if you had a contractor walk it with you initially and gave you an estimate, essentially getting an inspection before the offer.Also looks like you took an ARV given to you by the agent at face value.  

I'd also suggest finding your own rehab estimates as well after walking through.

I'm curious what your original rehab and ARV estimates were.

One of the properties I'm getting appraised .I have A general contractor that already drew up a estimate of 160,000$ .to fix up an repair.

#13 is a buy/fix/rent project near 140th & 11th in Grandview south of Main St.  3/1/0  Bought for $35,000 cash deal the rehab estimate is $8500.  

However, if you will let me come out and inspect the property, I can get you an estimate which reflects the true value of the house."

The estimate was $4,200. 

Is there a difference between the estimates for repairs (e.g., on a buy and hold before you rent it) contractors usually give to investors vs the estimates/pricing usually provided to your average homeowner wanting to update their house?