Textbooks versus Packets

I'm planning my courses for next semester. Textbooks cost a lot. Viscusi, Vernon and Harrington's regulation text costs $88, which is typical. Are they worth it? Yes, probably. The cost of me, the professor, and the time cost of the students is much higher, and a good text is valuable. But there is one big problem. Students don't keep their texts. They resell them. This loses them one of the most important parts of their education. If they realized this, they wouldn't sell them, even at the current high prices, but they don't. It might nonetheless be important. If I assign them a packet of readings instead, will they keep the packet? If they do, maybe that is enough of a teaching improvement that I should do it.