Do you say you're gonna go on and earn a cheeseburger or that you're going to go earn a house? No, you're gonna go buy that cheeseburger and house.
English
-
On the other hand you can't say that I didn't earn the cheeseburger, because the money I used to buy it is just a placeholder used to simplify the exchange of goods and services. Earning money and using it to buy something is not any different than earning the thing directly, besides that it's a lot easier to carry cash in your wallet than anything else.