Buyer’s regret is real, and my clients often express regret when we're in an organizing session. I’ll pull out a leather handbag or a pair of shoes from the back of the closet or from a box on the top shelf, and ultimately they’ll cringe and tell me they dislike the item, but they’re keeping it because they spent a lot of money on it.
So I may challenge them to think about the item differently by asking: “If you keep it in the closet for another year, will it gain value?” In some cases, it might. In other cases, it's just adding to their clutter and their guilt.
Some mistakes are expensive, but don’t pay for a mistake with extended regret. Instead, learn from the mistake, forgive yourself and move forward.