A vendor imposed a condition that a prospective purchaser has to pay him some compensation if he does not buy

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Check below answers in case you are looking for other related questions:
It is not permissible to sell something that will be used for sinful purposes
Is it permissible for people taking part in an auction to ask someone present not to increase the price?

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Related Answers:
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Bay’ al-Wafaa’
It is not permissible to sell something that will be used for sinful purposes
Is it permissible for people taking part in an auction to ask someone present not to increase the price?

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