A headline maker or taker fee is only one line in a purchase. Funding fees, card processing, exchange-rate conversion, spread, and withdrawal fees can materially change the result.
Spread is the difference between the market reference and the price at which the service is willing to buy or sell. A zero-commission purchase can still be expensive if the spread is wide.
Compare the final bitcoin received for the same cash input. If you plan to self-custody, include the withdrawal fee rather than treating it as an unrelated future cost.