What is the ruling on selling a gold item at a price set by the seller, with payment of its price made after the sale along with taking a percentage of it, and is it permissible to specify the amount or the percentage, and what is the legitimate alternative if that is not permissible?

There is no objection to specifying the wage from the price of the commodity or otherwise, on condition that it is known. If it is not specified, then a reasonable wage is obligatory. It is permissible to take a wage for brokerage and mediation, and this is indicated by the Almighty’s saying: "And for him who brings it is the load of a camel, and I am responsible for it."