That's more or less the way auctions work. The auctioneers expect payment in full in 1-15 days or so depending on where you are and the type of auction. Certainly not enough time for you to get contingency financing on the property.
In states like Texas you need 100% day of, I believe. Florida has unique rules (they all do) as well.
Curious, what made you think purchasing the course was worthwhile? What was their pitch vs delivery?
I don't do auctions... but there are proxy services out there and I believe some will buy it for you so you can HML. Don't take this as fact, rather a creative idea that I think I remember seeing.