The moment before checkout
You spot something on your feed. It looks good, people are talking about it, and the link is right there. The buying pause begins at precisely that moment. It is not a rule against shopping. It is a short break from urgency so you can decide on your own terms.
Step one: save it somewhere else
Copy the link, take a screenshot, or write down what you want and its price. Then close the shop. You can use the pause on this site to keep a note on your device and see when three days have passed.
Step two: ask what changed
After 72 hours, revisit the item. Do you still want it for the same reason? Will you use it? Is it replacing something that works? Would you buy it if nobody saw you own it?
Step three: choose
You might buy it, wait longer, look for a second-hand version, or let it go. Each is a valid result when it is your decision.