Imagine a situation where you own a house and a piece of land it's built on. You estimated the value of the whole thing to be $500k. One day someone knocks on your door and offers you $2m all of a sudden. Will you sell or suspect they know more than you? Maybe there's an oil deposit underneath your house? Maybe there's geothermal energy source? Maybe an international company has plans to build a facility nearby and will need your land for whatever price?
If it were me, I would refuse to sell this property right now, even though they offered a very high price compared to its real value.
Firstly, I don't want to sell this property right now because I am living comfortably and satisfied with it. I love my house, I like the neighborhood, and I have no plans to move anywhere.
Second, I doubt the buyer knows anything that I don't. Maybe there's a valuable natural resource lying under my land, or maybe a company plans to build a facility nearby and needs my land. If I were to sell this property, I would probably be Hatred after learning the real reason behind the buyer's offer.
Third, I don't want to be forced to sell my property. If I agreed to sell for $2 million, I would feel like I was being ripped off. I would not feel comfortable knowing that I could have sold my property for a much higher price.
Of course, I may still consider selling this property in the future, but only if I have enough information and am sure that it is the right decision. If I still do not want to sell after learning more about the offer, I will decline.