What is the commission paid to a primary broker/dealer for a US Treasury bill?

Factual Questions
1

I assume it not like my $10 stock brokerage fee.

Use $10 million in a single bank-to-bank transaction as an example.

Thanks.

2

You can buy them direct from the US Treasury with no fee at all:treasurydirect.gov.

So why would you pay any broker any fee?

3

Because the brokers winning competitive bid , with fee on top, can be cheaper than the individuals non-competitive bid …

You can see that only the broker can make competitive bids.

The non-competititve price is the WORST price at the competitive auction.