The Crisp Habit That Would Cost You £1 Million

Here’s a fun bit of maths to open with: if you had one packet of crisps a day, at a pound a packet, how long would it take to spend a million pounds on crisps alone?

Two thousand, seven hundred and thirty-nine years.

So no, your crisp habit is not going to cost you a million pounds. Nobody’s is, not in one lifetime, not on crisps alone. But that’s not really the interesting question. The interesting question is what your everyday small buys — the ones that feel too small to matter — actually cost you once you stack them up, and what someone else is making while you’re not looking.

It’s never the big purchase that quietly drains you. It’s the four small ones you don’t think twice about.

The four everyday buys

Let’s take four things most of us buy without a second thought — a bottle of water, a takeaway coffee, a packet of crisps, a shop-bought sandwich — and look at three things: what you pay, roughly what the industry margin is on that item, and roughly what it costs to make or get the equivalent yourself.

Item	Shop price	Typical industry margin	Make it yourself	Daily saving
Bottle of water	£1.50	~35%	Tap water, next to nothing	£1.50
Takeaway coffee	£3.00	70–85%	~£0.25 at home	£2.75
Packet of crisps	£1.00	30–55%	~£0.25 homemade	£0.75
Shop sandwich	£3.50	6–15%	~£1.20 homemade	£2.30
Total	£9.00	—	£1.70	£7.30

Margins are general industry averages (based on published industry data), not figures for any one specific brand — they cover things like ingredients, packaging and production, not necessarily full overheads. The sandwich shop margin looks low because a sandwich shop’s costs include labour and rent, not just the filling.

What £7.30 a day actually adds up to

Seven pounds thirty a day doesn’t sound like much. Here’s what it becomes:

• Over a year: £2,664.50
• Over 10 years: £26,645
• Over a 40-year working life: £106,580

That’s not a fortune from crisps. That’s a deposit on a house, from four things you barely think about buying.

This isn’t about never buying a coffee again, or feeling guilty over a sandwich. It’s about seeing the number clearly, so it’s a choice you’re making on purpose, not a leak you didn’t notice. That’s the whole game with money on a low or average income: not extreme restriction, just knowing where it’s actually going.

“But I make more money at work in that time”

This one’s worth taking seriously, not brushing off. If skipping the sandwich-making saves you fifteen or twenty minutes, and you genuinely spend that time earning, buying might be the smarter cash flow call. So let’s actually test it instead of assuming it.

Making all four things yourself takes roughly fifteen minutes a day, all in. Over a year, that’s about ninety-one hours. To match the £2,664.50 a year you’d save doing it yourself, that time would need to be earning you somewhere around £29 an hour — and every one of those minutes would need to convert directly into paid work.

For most people on a salary, that fifteen minutes in the morning doesn’t turn into £29 an hour of extra pay — it turns into a bit more scrolling or a slower start. If you’re self-employed or freelance and that time is genuinely billable, the maths can flip, and buying is the rational cash flow decision. Worth being honest with yourself about which one it actually is, rather than reaching for “I make more at work” as a reason not to look at it.

The health side of it

There’s a cash flow argument here, but there’s a health one too. Shop-bought sandwiches are, on the whole, higher in salt, added sugar and preservatives than something made at home, because they’re built to survive on a shelf, not to be good for you. Same goes for a lot of flavoured, heavily salted crisps versus a homemade batch where you control what goes in.

So the cheaper option and the healthier option often end up being the exact same option — make it yourself — which is a nice rare case of your cash flow and your health actually pointing the same way.

This isn’t medical or nutritional advice, just a general observation — if you’ve got specific health or dietary concerns, that’s a conversation for your GP or a dietitian, not a blog post.

If this is the kind of thing that clicks for you, I go into a lot more of this — proper break-even thinking, cash flow, building wealth without a big income — in my book, How to Build Wealth on a Low Income, which is £1.99.

Love, Vikki