I think the point is to introduce more desirable items for kyoubai. Since it’s not that hard to get a good set of files, and after that you’re just spinning the wheels and collecting. But people do bid on things simply because they’re rare, and people may well end up bidding extra intensively on an item that they had a part in creating.

But basically, I think it’s so there’s a consistent supply of rarish special kyoubai auctions (like the headset, but less powerful probably), to keep people interested and to sink a lot of flezz.