Auction - Buyer premiums and how they work?

[Tyler Bowes]

I am looking at a home as a primary residence, and it is listed for auction. Reserve is undisclosed and buyer premium is set at 10%. I've never participated in an auction before, so was hoping for some guidance. Here are some of the details regarding the scenario:

- Taken off market last month at 499,900 

- Listed for auction yesterday with undisclosed reserve

- buyer premium of 10%

- Open for cash and financed purchase

- down payment of 10k due by end of day of auction

My scenario would be to seek financing. For simplicity, say winning bid was 400,000. I would owe 440,000 due to buyer premium. Other than traditional origination charges for completing a loan, does the buyer premium get applied to other traditional closing costs (title charges, etc)? Or is the premium on top of traditional closing costs.

Thanks in advance.