The utility of a single textbook approach can be questioned, of course. Using only a textbook can discourage students from reading widely, and to think that they can rely on one text - no matter how many times they are told the contrary. A single book can also encourage the belief that there is only one way of thinking; in the context of this chapter that is a serious problem.
An alternative approach could require students to buy several key texts. Barone (1991) reports that students were expected to buy one book per perspective studied, for example Dugger (1984) on institutionalism and Littlechild (1978) on the Austrian approach. Such a strategy will usually come up against a cost constraint.