Depends on what you're selling and who is buying. the bigger the publisher, the higher the price. They have larger budgets available because larger distrubition means higher profits. For instance, "regular publishers" can pay $500.00 to $10,000.00 for a cover, big name authors can get a million dollars up front money. the smaller publisher, the smaller the distrubition the less money is available. E-Publishers are usually small press. These prices vary greatly and can be a flat fee, to a percentage of sales. the more rights you sell the higher the price. The exception is work-for-hire, that's usually all rights, and little money. Why do it, because it is a good way to get published if you're just starting out. What rights you sell is important, it can mean additioal money. Understand First Rights pays the most. Secondary Rights pay less, you can sell electronic rights, (CD's Games etc), Movies Rights, Prints, Collecters Plates, Mugs, T-shirts, etc. I really pays to produce really good work, because the after market has such potental. Reputation also affects the price. Like anything else, a big name artist can command a higher price. The genre also determine the price. Children Books can be low or high depending on age bracket, number of pages, size, (size does matter)etc. I guess an average 32 page book would pay about $3500.00. Can you be more specific as to the kind of art, what publishers? Childrens Books, Magazines, Websites, Book Covers, Prints, Collectables, Games, etc, etc, etc? Define your Market. Take a long hard look at your work, does it look like your art? And remember never send a picture of a Cat to a Dog Magazine, No matter how good it is, they will never buy it.