Because of the power of attorney, the buyer does not need to meet the owner; Deciding whether to look at the house is the right of the buyer, and he has the right to give up looking at the house; There is no standard price for house prices, so it is hard to say that it is significantly higher or lower than the market price. Even if it is significantly lower than the market price, it can only be said that the buyer is speculative and cannot be considered malicious.
Of course, if the power of attorney is invalid, it will inevitably lead to the invalidation of the house sales contract. Therefore, the legitimate interests can be protected by claiming that the house sales contract is invalid.