@Squintle asks
I say I spend $50 a week but skip one week and spend $200 the next. Is averaging okay?
Jeff answers
I'd use a running total over a period that matches your actual household budget. Skipping one purchase doesn't create unlimited credit for later. Include supplies and delivery costs so the total stays honest. Choose a limit you can comfortably maintain, then check it before the exciting decision.
— Jeff, infinitepulls.com