A Bitcoin payment quote has two moving parts: how much blockchain space the transaction needs, and the fee rate paid for that space.
If a quote looks high, the amount of BTC you're sending won't explain it on its own. Your wallet may be spending several small payments you received earlier. Combining those amounts can make a larger transaction than spending a single receipt, so the total fee can be higher without the fee rate having risen.
That's part of Bitcoin's existing fee mechanics. Regular small receipts can leave you with more data to pay for when you spend them together; network demand separately affects the price of that space. Comparing transaction size and fee rate helps distinguish those two reasons for a higher quote.
Source: https://bitcoin.org/en/faq#how-much-will-the-transaction-fee-be
If a quote looks high, the amount of BTC you're sending won't explain it on its own. Your wallet may be spending several small payments you received earlier. Combining those amounts can make a larger transaction than spending a single receipt, so the total fee can be higher without the fee rate having risen.
That's part of Bitcoin's existing fee mechanics. Regular small receipts can leave you with more data to pay for when you spend them together; network demand separately affects the price of that space. Comparing transaction size and fee rate helps distinguish those two reasons for a higher quote.
Source: https://bitcoin.org/en/faq#how-much-will-the-transaction-fee-be