Do you mean of the VP? Like buying VP bundles?
Across all the different content we offer, it would be extremely difficult for us to make sure that there's always a VP bundle that captures exactly the amount players need. And I don't just mean as a game: purchasing in-game currency is done in collaboration with a central Riot team that handles it for League, Legends of Runeterra, and VALORANT.
When we've chatted with players about this, we've learned that it's frustrating for a first purchase, but the frustration usually goes away pretty quickly, because it's very, VERY rare that players only buy cosmetics once in their entire lifecycle. It almost always gets put towards a later purchase.
Please know, though, that this is something on our radar. We're keeping tabs on how players feel about this, and if we have good reason to prioritize this issue over other issues, we'll do that :) I hope this makes sense!