Is it permissible to pray in shoes if there is no impurity on them? And is there a specific value for profit in sales, such as it not exceeding half or a quarter?

Praying with shoes is permissible if they are free of impurities. There is no limit to profit, unless the buyer is ignorant of the value, entrusted the seller, and sought his advice. In this case, the sale is to be revoked if the profit exceeds one-third or more, and this is the preponderant opinion.