Or maybe the spread is different for different giftcards and countries.
I think nostr:npub1lyqkzmcq5cl5l8rcs82gwxsrmu75emnjj84067kuhm48e9w93cns2hhj2g is being tricked because he is believing the Bitcoin price Bitrefill is showing him. The cards may have no markup, but the intrinsic Bitcoin price they use to do the conversion is fraudulent. I don't know if this is the explanation, but could be. That's how many of these loved "Bitcoin-only" companies trick people.