At the risk of coming off as a curmudgeon, what you’re describing is actually a version of piracy. The law provides for you to make personal backup copies of media you own. You’re absolutely entitled to make a copy of something you have on vinyl and put it on a CD, or to copy a laserdisc onto a DVD. But you must either retain the original item, or destroy it. You cannot transfer the original item to another owner while retaining the backup copy. Once you’ve transferred ownership of the original item to someone else, you’re no longer entitled to have a backup copy of that thing which you no longer own.