You definitely need to be able to spend 30m when the position demands it, but it's not as if teams with better scouting than ours haven't been finding gems in the 10-15m range in the last 2 years. I can't be bothered to do an extensive search, but both Semenyo and Kluivert cost B'mouth in that range in 2023, and Hudson-Odoi went to Forest for about 3m.
Our scouting is just fucking awful and has been for years (with the very small exception of when we've been able to convince high-profile youth players like Tino and Lavia to join, which isn't the same at all).
(Obviously Hudson-Odoi also a known quantity, but he was just so absurdly cheap I include him for comparison anyway)