Question How Often Do Rick's Guidebooks Go on Sale?

A few years ago, I managed to grab several of Rick's Guidebooks during what seemed like a sale, possibly tied to the COVID shutdowns. Since then, I've been keeping an eye out for similar deals but haven't seen anything as good. Does anyone know how frequently these guidebooks go on sale? Are there certain times of the year or specific events that trigger discounts? I'm planning my next trip and would love to stock up on updated guides without breaking the bank.