Actually the acronym idea might work.
Read and trash edition (RAT)
Read and keep edition (RAK)
Read and toss would work as well but that might confuse our UK friends.
I agree that many people don't care if you can read it more then once. My mother doesn't understand why I buy books when you can get them for free at the library. I like to think I can read them again in the future but I'm realizing it's not likely to happen. Mainly I want to compensate the author.
I would like to have the option when I buy the book though as to the life expectancy of it (paperback vs hardcover idea). Some reference books I'd like to keep for a long time.