You're absolutely right, Dragon Token is stupidly overpriced and is the result of poor decision-making, as usual. Transmuting it costs as much as doing breakthrough with the normal path, and it shouldn't be nowhere near as expensive as a Sacred Vial (which imo is also stupidly expensive but that's just me talking).
It should cost 20 Polished Scale Fragments at most. I mean, events are meant to be somewhat fun and rewarding, right? But ofc, NCSoft has to ruin everything with their greed.