CG The genealogical publishing community is a small one. And books and publications are expensive. But you are not being ripped off.
Demand is the key word.
Unfortunately, most genealogical publications do not sell millions or even thousands of copies. The self-publisher of a family history book is soon made aware of this fact. Since most genealogies and publications of interest to genealogists are published in small runs, the cost per unit is usually expensive. Tracing ancestors can be expensive and few researchers can afford to buy all the books and publications available about their families or the localities in which they lived. You can save some money simply by being aware of what is in print and then trying to locate copies in your local libraries, through interlibrary loan or via the circulating libraries of New England Historic Genealogical Society and National Genealogical Society, if you are a member of those organizations.