Thanks for the cheap buff pots.
Please consider extending the expiration date on the event buffs. If you take 19 boxes everyday and get 19 items from each, you end up with 2,527 buff pots. Emperor buff lasts for an hour and the others for 30 minutes. So using 30 minutes, you can use 48 items in 24 hours x 6 buffs, or 288 per day; 2,016 for 7 days (emperor buffs would make the used amount lower).
Can you extend the expiration by week, so we can use them all?