Hi I am trying to creat what I though would be a simple formula could anyone please help out. I need to calculate a price to charge a client based on a specific profit I want to get from these simple variables

1) my cost of the product ( static # )
2) my commission on the sale of the product ( static # )
3) what i need to charge the client to get a $50 profit

ie
(My commission ) $200 minus ( my cost ) $250 I need to charge (?) to recieve a $50 profit