The Inconvenience of Buying/Selling Gamma Wave Items

I have a question. Why do the sales histories for all knives (regardless of phase) appear on the Gamma Wave item listings?I go to the M9 Gamma Wave Phase 2 listing, which costs 120,000, but the sales history shows me a sold knife from Phase 1 or Phase 3. It’s simply impossible to track the trend for this knife this way, since the phases just get mixed up.Why can’t you add a separate sales history for each phase? After all, you can select a specific knife of a specific phase on the website.