1. Here you can define a custom buyer's premium structure for this auction that would override the one setup at Settings >> Buyer's Premium. If you leave this part untouched, the system will always fall back to the global buyer's premium settings.
2. The range start.
3. The buyer's premium amount for the range.
4. This determines a minimum buyer's premium below which the BP will never go when invoices are generated.
5. Apply stepdown calculation: When this is checked, then the buyer's premium due will be calculated by applying the configured percentage to each respective range, rather then to one flat hammer price only.