For small transactions, the flat fee represents a disproportionately high effective percentage cost — a $0.99 fee on a $10 purchase is a 9.9% fee before even accounting for the spread, making micro-investing in crypto very expensive on this platform.
Coinbase's dual-fee structure means retail users pay both an embedded spread (up to 2% of transaction value) and a separate explicit transaction fee on every buy or sell, making the true cost of trading higher than either charge alone suggests. Users paying with debit cards or instant bank transfers face significantly higher fees than those using standard ACH transfers, which can materially affect the economics of small or frequent trades. You can see your exact total fees — including the spread — by clicking the 'Preview' button before confirming any transaction in the Coinbase app or website.