Not sure why people don't put a large price sticker on the table cloth in front of every knife, maybe they are shy or are fed up with people who compare the prices with Wal Mart. In any case the price should be there in case a serious knife person comes along and is too shy to pick up the knives and look at the sticker on the back. Another added touch is information on the knife materials used, this helps initiate conversation with the public.
What attracts people to a show, variety, presentation, promotion and friendly approachable vendors. Once you have convinced the people to attend the best way to get them to come back is to make them feel welcome and part of the show. For this the vendors have to be encouraged to get involved with the public, smile, chat and encourage questions.