What is the ruling on placing concealed prizes inside merchandise for sale, and what are the conditions for that?

For it to be permissible to place hidden prizes inside goods, the price of the commodity must not exceed its market price. Otherwise, it is forbidden due to the elements of gharar (uncertainty) and maysir (gambling) present therein, as the buyer expends money for something unknown. The Prophet, peace and blessings be upon him, forbade sales involving gharar. Furthermore, whether the buyer obtains the prize or not is considered maysir, and maysir is an abomination from the work of Satan that engenders enmity and hatred.