This is a really good question and I too would love to hear from other members, especially those with sales experience. I wonder what kind of arrangement sales people are looking for? If sales people are open to commission only what percentage makes it worth theie time? If sales people need some type of base payment, I would really like to know what they require? what kind of arrangement keeps a sales person motivated to sell?
A good way to decide is to figure out A) if sales for you is their only gig, and B) if so, what would be a decent monthly "salary" to make it worth it for them. From there, figure out what % of your sales gets them to that point. For example, if the sales person wanted to make $5000 a month, and you offered 10%, they'd need to sell $50,000 a month. If they have other sources of income, then less might be acceptable to them. It will also depend on how much responsibility you want to give them and what your production capacity is (if you can't produce $50,000 worth of chocolate, then recalculate based on what you can make).
Ultimately you will have to just put an offer out there and negotiate based on individual needs.
As far as a salesperson is concerned, unless you have a well established mix of product/pricing/historicals, it will be difficult to obtain a qualified person, even if on a part time basis.