I just spent $500 in workout gear within the past 3 days. Normally I don't spend any money, but I "had" to have it. I still feel like I "have" to have it... but I know my mood is elevated. It's slowly returning to normal, though.

I know my manic/hypomanic tendencies, so I keep receipts nowadays. That means if buy anything stupid, I can usually return later... or at least get a store credit.

Keeping receipts is a good habit. Try keeping them whenever you go shopping.