If the changes aren’t that minor, then people would certainly gain extra value from buying the 4th edition instead of freely getting the 1st.
If the changes were minor, then maybe it would stop, say, a textbook company from releasing a zillion versions of the same book with minor changes or the question ordering switched in order to extract money out of the next class of students instead of simply allowing them to buy the previous edition used. ;)
If the changes were minor, then maybe it would stop, say, a textbook company from releasing a zillion versions of the same book with minor changes or the question ordering switched in order to extract money out of the next class of students instead of simply allowing them to buy the previous edition used. ;)