Interesting that a majority of them are not graded/authenticated.
You paid about $375 for the Cas coin in August 2023 and they have it listed at $165
Were you able to tell them the starting price or do they decide for you?
https://bitcointalksearch.org/topic/auction-20112012-casascius-redeemedblank-1-btc-5-btc-5464284
https://bitcointalksearch.org/topic/auction-20112012-casascius-redeemedblank-1-btc-5-btc-5464284.msg62762976#msg62762976
https://subastas.tauleryfau.com/en/lot/25092024-3882-3882/767-3048-Monedas-Extranjeras
You can tell them de starting price, but It is better to have a low starting and let the market set the price.