I don't think the margins are that crazy. Looking at a bog standard 0603 0.1uF MLCC, they're often $0.02ea on a full reel of 4000 or $0.03ea at a cut tape of 10

I don't think the margins are that crazy. Looking at a bog standard 0603 0.1uF MLCC, they're often $0.02ea on a full reel of 4000 or $0.03ea at a cut tape of 100. So, Mouser makes a whole extra dollar to cut and bag a tape for me. For an 0402, they charge $0.02ea @100 or $0.011ea @50K. So, they make an extra $0.90 by letting me order 100 instead of 50K. 0603 10K resistor: $0.008ea @100 instead of $0.004ea @1000 (5000 is a reel). That all seems pretty fair to me.