[modeleh]

Although there is a risk of copyright infringement, as others have said some money is better than none. There will always be people who cheat and ride on the back of someone elses hard work. Everyone who has ever written a book is faced with your same problem.
My wife is into quilting and makes and sells patterns sold as a pdf. It seems to be the way to go to keep costs down and eliminates problems on your end related to paper/ink/production/time. The first one she did she gave away free so people could tell the quality and ease of use of the pattern. In your case, perhaps this could be a header pattern which is fairly simple. Now you have people out there that can see the value of your pattern first hand, but they didn't have to risk their money for a disappointment.
You have to consider the price point and how you want to sell them. And again realize that the more reasonable the cost, the less people will steal and reproduce them and the more people will buy from you ligitimately. You might do better to use the Wrigley gum theory of business here. Remember, he made a fortune selling a product at a nickle a piece.
If you sold the patterns relating to each section, you could sell them for less and sell more. Lets say you sell each for ten bucks. A guy needs to do the roof bows in his coupe. So he downloads the patterns for 10 bucks. Then a guy needs to do the rear door on the delivery. Ten bucks. But ten guys over the country see it and say, hey it's only ten bucks and click the buy it now to start the download. Now you just sold a hundred bucks with zero cost for paper/print/shipping. How much is a complete pattern going to sell for and will it be priced at the point you might only sell a couple a month. You generally have to discount the value of the individual items to sell something whole.
Keep in mind, I'm no business man, just a backyard jack of all trades so take it FWIW.