Question, do achievements from the standalone package operate separately from GTA4 if you have it?
I have TLATD, but I do not have TBOGT. I figure I might as well wait until this combined package is around $20 or so as opposed to paying a full $20 for just TBOGT over Live (unless that magically does on sale at some point). I wouldn't mind playing through TLATD again, anyway and extra achievements would sweeten it.
For future reference as it is sort of irrelevant at this point as there's no way I'd pay an extra 10 to just get repeated achievements.