My experience is you can narrow down the estimates by giving the sites more info that may not be available to them. Article in the WSJ today made the point that a number of states including (I checked—Illinois isn’t one of these states) Texas don’t even require public disclosure of the prices of actual sales. Then there are factors like you say your place was gut rehabbed—so how old is the roof, the major equipment like HVAC, water heater etc. Do you have anything of unusual quality like flooring etc. Since all the online sites have to go on is last sales price, square footage comps, number of rooms and other large scale factors—nobody has visited the property after all—they can make wildly varying assumptions. But most of the sites—Zillow certainly does—allow owners to supply missing details and granular facts that can replace assumptions.
Here’s the WSJ article:
https://www.wsj.com/articles/the-sta...s&page=1&pos=1