The problem of boosters is not solved by banning them. Not everyone would get caught, we would need some kind of new logs or eyes literally everywhere in the wilderness. It causes a lot of unnecessary work to the entire staff team, while having very little effect on actually preventing boosting.
Furthermore, what should be in this pkp shop? How would we go about earning the currency for that pkp shop? You barely included any details about the thing you're suggesting. A pkp shop wouldn't be a bad idea, it might encourage a lot more people to go pk. However nobody has managed to spend a bit of their time and actually write out a proper suggestion for one, instead of just plopping down a 1 sentence suggestion that everyone has already seen. Quite a shame.