Birthday Party

Morty's birthday is coming up and the whole family wants to organize a huge party. Rick was given the task to go and order $m$ dishes for the party. He does not like doing errands but since he loves Morty so much he agrees upon it. He went to an intergalactic restaurant where they offered that if he orders any one dish with the price of $x$ then he gets $k$ dishes for free whose price is less than