Dealers could bid online, private buyers couldn't. All in-person centres were closed due to Covid, so private buyers couldn't buy. It seems they still won't allow private buyers, even in person:
"I am not a member of the trade, how do I search for vehicles?
BCA is currently only open to trade buyers. Should you wish to purchase a vehicle then please let us introduce cinch.co.uk the faff-free car service. "
Here's the standard 'blue' BCA dealer fees:
I think with volume a dealer can get a discount of about 50% on the 'blue' fees - there are various tiers based on sales volume.
Theo