Originally Posted by Wuzzat?
My guess for the center value for several bids would be sqrt(15K x 50K) = 27K and I'd modify this estimate according to Web opinions and Web facts while correcting it for locale.
If the low bid/high bid were closer together, like 15K and 25K, I guess I'd say (15K + 25K)/2 = 20K for a center value.
If I'd guess between $1K and $200K for an interval estimate, almost certainly this would be right.
Right now the lower end of this interval estimate seem to be >$15K.
It dosn't matter, what ever information they get from here, it would be a guess at best or ads on line would only find a salesperson to come out and expand the price when they get there.
They still have to deal with contractors and there ideas or develope a plan to get quotes on. Whether the job done is good or bad the answer is still the same. It will be worth what they pay for it. There is no shortcut.