Toggle-able option in the workshop to receive a notification (just an alert like when you try to demote a player to nc) that your buff has ran out. Flashing from 10 downwards is fine to warn a player it'll run out soon, but sometimes I can't see those buffs due to how I set up my screen.
Could even implement an auto-rebuy as long as all conditions are met (not bought one today, got the trophy points etc)