There are established terms and practices in auctions, and this article explains Starting Price and Minimum Increment.
Starting Price
Bids are made upwards from the starting price. The starting price is the base from which bids begin.
The starting price can be €0, and it is advisable to set a low starting price so that the auction can start freely.
Minimum Increment
The minimum increment is the amount by which a bid can be increased at minimum each time.
An individual bid can be greater than the minimum increment, but not smaller.
Example:
The starting price of the item is €100 and the minimum increment is €20. Therefore, the first, lowest possible bid is €120. Each increase after this must be at least +€20 as per the minimum increment.
The seller representing a company determines the starting price and minimum increment for the item.
In a consumer auction for a private individual, the starting price is €0 during the item's first auction, and the minimum increment is determined by Huutokaupat.com customer service based on the general value of the item and the target price given by the consignor.
Both the starting price and the minimum increment vary by item.