As long as the seller wants and is willing to pay.
One Day-- but it can take up to 24 hours to appear/ index.
Three Days- like One Day, time is lost to indexing. Popular with scammers.
The above are being discouraged by eBay as being inefficient.
Seven Days- The most popular and efficient auction listing.
Ten Days - The most discouraging auction listing for impatient buyers.
30 days- The most common listing for Store/Fixed Price listings
Good Til Cancelled- Also 30 days but automatically relists until sold or cancelled. Low labour cost for sellers.
Fees are all over the place, from free to 30 cents, depending not only on the category of products, length of listing, and options like sub-title, but also on promotions (50 Free Auctions!) and discounts to Top Rated Sellers, etc.
