Why are operator voice packs so expensive?

I noticed Aina now has a voice pack available. 8th MS Team is my absolute favorite Gundam series so natural I looked into it. But $45!? For one voice and 53 tokens? Tokens can be easily obtained over time so why don't we have an option to just buy the voice pack for a lower price. I'm not buying it of course, but who here is coughing up $45 a pop for voice packs? Geez I'll just use the ones I unlocked in Code Fairy.