I think you need to have different BIN prices on different venues, if only to account for the varying commission rates.
That's why this example is even weirder, as GoDaddy has the highest commission.
P.S. Bob, I think the multiple marketplace links is genius, as I have sold many domains to companies that 'will only buy through GoDaddy", even if the price is higher than on Dan. Giving the buyer a choice of options is never a bad thing, as some could have existing GD (or Afternic or Sedo, etc.) accounts and may not want to buy anywhere else.
Plus, I think the presence of well-known names like GoDaddy and Sedo on your lander will give greater credence to your listing, and may increase offers or sales at other venues like Dan or Uni.
I think at some point in 2022 I am going to give Domain.io a shot and see if conversions go up. Just the auto-TXT listing, auto-delete-when-sold, and auction tracking features look to be worth the monthly cost.