Most people buying crypto notice a single number: the fee the exchange prints in bold. But that's only a third of the story. There are three costs, and two of them hide inside the price itself, so you never see them as a separate line on your receipt.
Let's walk through them using one specific purchase.
What's our example?
Say you want to buy bitcoin for 10,000 CZK. Your bank sends koruna, but the exchange trades pairs in US dollars (USD). This is a common situation, not the exception. This is exactly where all three costs appear at once.
We'll go through them in the order in which they hit your money.
Cost 1: How much does the fee itself cost?
The fee is the amount the exchange charges for executing the trade. It's the only one of the three costs you usually see spelled out in black and white.
A typical fee on a retail purchase ranges from tenths of a percent up to a few percent. Let's say you pay 1%.
On 10,000 CZK that's 100 CZK.
People understand this number. It's transparent and easy to compare across exchanges. The problem is that many stop here and assume the costs end with it.
Cost 2: What is the spread and why won't you see it on your receipt?
The spread is the difference between the price at which someone is selling at a given moment and the price at which someone is buying. You never buy at exactly the "price on the chart." You buy at a slightly higher price than you'd sell for in the same second.
Think of it like a currency exchange booth at the airport: the board shows two rates, buy and sell, with a gap between them. That gap is the spread.
In a very liquid market, where there are lots of bids and offers close together, the spread tends to be small. For less-traded currencies or a thin market it can be large. This is where liquidity comes in, meaning how easily an asset can be bought and sold without moving the price. (We cover it in more detail in the liquidity glossary entry.)
Let's say the spread on our trade is 0.5%. That's another 50 CZK you'll never see as a line item on an invoice. It's built directly into the price you're buying at.
That's why two exchanges with the same 1% fee may not be equally expensive. The one with the wider spread costs you more, it just isn't visible.
Cost 3: What happens when you pay in koruna and the exchange trades in dollars?
This is the cost most people forget entirely: the exchange rate on the fiat leg of the trade.
"Fiat" is an ordinary state currency (koruna, euro, dollar). The "fiat leg" is the part of the transaction where your koruna is converted into the currency the exchange trades in.
When someone converts your koruna into dollars, they use some exchange rate. And that rate is almost never exactly the interbank rate you see on Google. There's usually a markup added. Let's say 0.7%.
On 10,000 CZK that's another roughly 70 CZK.
This cost is sneaky, because it looks like "just a currency conversion," not a price for crypto. But it leaves your wallet just as really as the fee does.
So how much did the purchase actually cost?
Let's add up all three costs on our model 10,000 CZK trade:
| Cost | Rate (example) | How much it is |
|---|---|---|
| Fee | 1.0% | 100 CZK |
| Spread | 0.5% | 50 CZK |
| Fiat-leg exchange rate | 0.7% | 70 CZK |
| Total | ≈ 2.2% | ≈ 220 CZK |
Someone who watched only the fee thinks they paid 100 CZK. In reality they paid roughly twice that. For bitcoin worth 10,000 CZK they actually received an asset worth about 9,780 CZK.
Important: the numbers in the table are an illustrative example, not measured data. Actual rates vary by exchange, currency, volume, and moment. We don't have a live value to plug in here, so we're not inventing one. The point of the example is to show the structure, not a specific price.
Why does it matter which cost hides where?
Because each of the three behaves differently:
- The fee is the most visible and the easiest to compare.
- The spread changes with market liquidity and with what you're buying. For large, heavily traded assets it tends to be smaller.
- The fiat-leg exchange rate only arises when your currency isn't the one the exchange trades in. Avoid it and it disappears; don't, and it can quietly be the biggest of the three.
An exchange boasting "zero fees" may have its revenue hidden in the spread or the exchange rate. Zero on one line doesn't mean zero overall.
What should you now be able to do?
After reading this article you should be able to:
- Recognize three separate costs instead of one.
- Ask, for any purchase: "What's the fee, what's the spread, and what currency does the exchange actually trade in?"
- Estimate the approximate total price as the sum of all three, not just the visible fee.
- Understand why two exchanges with the same fee may not cost the same.
This isn't advice on what to buy or where. It's a tool for reading the price, so none of those three layers catches you off guard.
What remains uncertain?
The specific size of each cost is variable and we're not measuring it here. The spread changes in real time depending on market conditions. Exchange-rate markups differ between providers and aren't always disclosed as a separate item. And some exchanges combine these costs in ways that make them hard to separate. So there's no universal "how much it costs" number. There's only a method for asking the questions, and you now have it.