Persons who actually bought and played the game would likely never say this (excluding a few anomalies). For my money, there is no doubt this game was worth it with or without the Halo 3 Beta invite. That was just icing on the cake.I am more upset that people are complaining they bought the "shitty GTA clone" just for the beta, than the beta being delayed.
On a side note, I wonder if Crackdown will get a big boost this month by people looking to get into the Beta at the last moment? It'll be interesting to look at sales numbers at the end of May and see if this had an effect. If so, MS will effectively have monetized access to the Beta without necessarily appearing to have done so. Smart move if it pans out. Of course, they may have already accomplished this with the initial sales of the title, but it's hard to know how much it would have moved sans invite, while any boost this month will definitely be attributable to the Beta invite.