You are at the shop with a £5 note. There is a fizzy drink and crisps at the till, and the pen you actually came in for. Grab the snacks and the pen has to wait. That tiny tug-of-war at the counter is the whole of smart spending in one moment.
Needs versus wants
A need is something you genuinely must have to live and function: food, water, warm clothing, a safe home, basic schooling. A want is something that is nice to have but you could manage without: sweets, the latest trainers, a games top-up.
- Grey areas exist. A phone can be a want (for games) and part of a need (staying safe and reachable). A coat is a need; a designer coat costing four times more is mostly a want.
- The test is not the item but the reason and the amount you spend on it.
Opportunity cost
Every pound you spend on one thing is a pound you cannot spend on anything else. What you give up is called the opportunity cost. If you spend £8 on a cinema ticket, the opportunity cost is whatever else that £8 could have bought — a book, or eight more weeks of saving toward a bigger goal.
Value for money
The cheapest option is not always the best value, and neither is the priciest. To compare fairly, work out the unit price — the cost per gram, per item or per use.
| Pack | Price | Amount | Per 100g |
|---|---|---|---|
| Small | £1.20 | 200g | £0.60 |
| Large | £2.50 | 500g | £0.50 |
The large pack costs more overall but is better value per 100g — as long as you will actually use it all.
How shops nudge you
- Adverts and "buy now" buttons are designed to make you act fast, before you think.
- Sweets at the till, countdown timers and "only 2 left" messages push you to grab, not weigh up.
Three simple habits fight back: wait 24 hours before a non-urgent buy, compare at least two options, and make a list so you buy on purpose, not on impulse.