No, don’t.

Instead, examine that thought process and ask yourself “Am I sure I need it?” and “why?” five times in a row. If you find yourself lost in a train of thoughts and daydreams, take three deep breaths and actually count those breaths. Instead of opinions and daydream why that stuff matters to you, look for facts about it that you will need to consider before buying. The entire process should take no more than five minutes but in the end you will end up being a rational buyer or learn to happily forego. Much easier, kinder and gentler than punishing yourself point blank, or end up being on an extravagant guilt trip.