I hoped this would explain the anomaly in AMD EPYC 3rd gen Milan pricing for the 24 core "F" (frequency optimized) parts being cheaper than the 16 core ones, but I still can't see any hint to the reason:

    model  | cores | price |
      73F3 |    16 | $3521 |
      74F3 |    24 | $2900 | <- cheapest
      75F3 |    32 | $4860 |

Same for 4th gen Genoa :

    model  | cores | price |
     9174F |    16 | $3850 |
     9274F |    24 | $3060 | <- cheapest
     9374F |    32 | $4850 |

The 24-core parts have the same number of CCDs, and thus same total L3 cache, and a higher turbo than the 32-core parts.