In this context, "pump" means the same thing as "inject" or more concretely "put into." Think of "pumping gas into a car." This is introducing something (gasoline) into something else (the car). Likewise, you can say "revenues/income" were "pumped" into the "company," in a figurative sense. So in the sentence, "revenues were "pumped straight back" into the company" means the money generated from the price premium was put right back into the company.

Pumped? What is this?))