thawk's advice,
"Take great pictures, show knife open and closed, both sides. Show all boxes papers etc.
Write honest accurate descriptions. State the closed length of the knife.
Low start price, get people bidding early, and several interested. Once certain people start bidding, they will keep bidding.
Certain interested bidders might not be able to afford too many at once, and you want a following."
I only buy knives and very seldom sell them. Although, I have seen so may knives sell for very low prices - because the seller tries to sell too may at once, or posts very poor photos.
Like thawk, of my opinions are based on buying, and watching for many years.
BY THE WAY: EBAY BLOCK AUSTRALIAN BUYERS, IF YOU USE THEIR POSTAGE SERVICE.
This is what comes up when I try to bid;
We are sorry but the item you selected may not be purchased due to Seller shipping restrictions, country specific import/export or other relevant restrictions.
When I email the seller they can not adjust this - then, often the sell has sent the knife to a friend in the US for me.