Answer: [By Dr. Manzur-e-Ilahi]
Praise be to Allah.
It is NOT permissible to pay money or anything else (cash or kind) for du’a. Du’a is an “act of worship” and no act of worship is valid unless it is done ONLY for/to Allah – an act of worship can not be performed in exchange of anything.
However, any Muslim can pray for another and you can ask anyone to pray for you.