I agree with this. It is not the high price of texts I am bemoanig here. I made peace with that long ago. I just want to be able to keep my etext as I would keep any book - even if if costs more to do so. If they want to have a etext rental program then develop a differential pricing scheme. But at this time I have no option to keep my etext. It has really limited the way I envisioned using my eDGe.
BTW - it does look like the EPUB format books in the eDGe bookstore do not expire. However, the majority of mainstream etexts (those from Cengage and McGraw-Hill) all do.