SPENDING AND FREEDOM
What does a purchase really cost you?
A price is only what leaves your account today. The full cost includes the growth and future freedom that money could otherwise buy.
The price tag tells you what leaves your account. It does not tell you what the choice costs your future.
Calling a $5,000 purchase “two and a half months of a $2,000 salary” is usually misleading. Most of that salary already pays for the rest of life. The purchase uses the smaller part that could otherwise increase your wealth, and that money loses every future return it might have earned.
Do not compare a purchase with your whole salary
Someone receiving $2,000 a month and spending $1,900 is adding $100 a month from cash income to their wealth. A $5,000 purchase is not merely two and a half months of income. It equals 50 months of that current cash saving.
That is still not the complete answer. Existing investments may also be growing, debt may be falling and income may vary. A useful account combines all of those changes and compares the financial path with and without the purchase.
Money spent today cannot keep growing
At the approximate 4.75% annual return after inflation used in this illustration*, $5,000 roughly doubles in purchasing power every 15 years. This is an illustration, not a forecast, but it exposes the opportunity cost that salary division misses.
Seen the other way around, something that uses $5,000 of capital today would use only half of the roughly $10,000 this money could become after 15 years. Spending early in the journey can therefore cost much more future freedom than spending the same amount later.
The cost changes as work becomes optional
A purchase may consume many months of saving and delay the point when investments can carry more of life’s costs.
A scenario can show whether this decision moves the date when paid work may become optional.
The cost can become less future wealth rather than more working time, provided spending still fits comfortably inside the plan.
That final purchase is not literally free. It still means giving up other choices or leaving less money invested. But once a person has more than enough for the life they want, the marginal usefulness of accumulating still more can be low. The expense may cost no additional working time at all.
A worked example inside the account
- Invested now
- $100,000
- Net cash income
- $2,000 a month
- Spending
- $1,500 a month
- Invested each month
- $500
- Investment
- World stock market index fund
- Expected real return
- Site’s editable default*
This example starts in September 2026 and uses the default costs and 2.5% inflation assumption, giving about 4.78% expected annual real return before personal tax. The comparison follows when that expected return first equals the $18,000 spent in a year. Paying $5,000 from the portfolio today changes only one input.
At the original date, the trip path has about $366,900 in today’s purchasing power, roughly $11,100 less than the starting path. The difference is larger than the original $5,000 because the money spent can no longer compound.
A lower saving ratio makes the effect larger
The same price can have very different consequences. Keeping income and the $100,000 portfolio unchanged, a person who spends $1,900 and saves only $100 a month takes much longer to replace the money.
The calculation is not telling you not to travel
A trip can be one of the best uses of money. The purpose is to replace a misleading comparison with an honest choice: knowing that this particular trip may mean six more months before work becomes optional, is the experience worth it?
If the answer is yes, spend without pretending it costs less than it does. If the answer is no, a cheaper way to enjoy the time may buy more freedom later. Saving is not merely accumulating money. It is also buying future time.
A full account can copy your plan, add a trip, car, wedding or renovation, and show the effect of both the price and the investment growth no longer earned.
See what the full account adds →