If you find a deed involving your ancestor have you determined if the price is relatively consistent with contemporary market prices? Keep in mind that “contemporary prices” need to be during the same time period for property that is roughly equivalent in terms of its worth.
If the price is lower than typical, then there could be a family relationship, there could be some “behind the scenes” (undocumented) financial activity taking place, or both. But there’s usually a reason why someone would buy or sell something at less than the market value.
You may not be able to determine what that reason is, but knowing the relative value matters.
One way to determine the price of other properties is to look at other deeds recorded during the same time period.