How Much Soap or Products Should You Bring to a Craft Show or Market

Earlier this month, I went to the Fremont Festival of the Arts.  At this particular arts and wine festival there were about five different vendors selling soap from cold process to melt and pour. I have never thought of selling my soaps at a festival but many have and probably wonder what would be the correct amount to sell at a show.  Well, there is no definite amount of product you should bring to a show.  But what would be the best way to determine that?  I would not know that but I found a posting by Erica of Bath Alchemy titled How Much Soap or Products You Should Bring to a Craft Show or Market.