There always is issues when one party is more educated about a transaction than their counterpart. Real estate is a complex market, where realtors and other market participants have an asymmetric information advantage than people only entering the market infrequently. Especially on property not lived in or used often.
The person or entity seeking to attain the asset does not have a vested interest in ensuring their counterpart is well informed. Keeping the cost down is a significant factor in any purchase. Especially if the purchase requires additional investment or cost. While one may look at purchase and resale price, the cost of making the property market ready can be significant.
If a person is willing to sell their property, that person should do the research needed to get a clear picture of the value before selling. The seller controls the timeline and has the power of yes and no. Buyers want a quick decision, but sellers should take their time.
It makes perfect sense that people might pay more attention to values of properties they occupy than property they inherit, especially when their is either no urgency to sell or selling while in grief. In any transaction, people should understand the party operating in the industry has more knowledge of the value of the underlying asset. Be weary to accept the initial offer.
Too many people are averse to negotiating because it requires confrontation. But, when money is involved, do not be afraid to ask for your full value. The worst that will happen is you get a no. Always counter. Always know the value of the asset.