I believe that this is a suggestion that needs to be merged with the Booster feedback on the Studio Area. I'll merge this which means the game team will keep an eye on this and will read the suggestions.
This doesn't mean a change will be made but know that the Studio is seeing it 😉
Hi @stan1981 as Rancid says, no we can only buy shovels or throw extra points at the rancid levels with beans along with buying companions. I have a guide here to boosters and their costs
Welcome to our friendly forums. In theory, King could make any booster they want and make it work in any way they choose. But nobody wants a game that is too easy. Even when my children were five years old, they liked a game with a challenge.