The disk that you get with the family pack is the same as the disk you get in the single user pack, the only difference is the terms of the EULA. So yes you could just user the single user disk over and over again but you would be violating the terms of the EULA. Whether or not you feel stealing software is apropraite is, I’m afraid, a moral decision that you will have to make by yourself. Apple has done the decent thing and treated you like an adult by not including any annoying online activation and charging a reasonable amount, and are expecting their customers to do the decent thing and pay for their software.