Everyone is obviously misinformed.
As of this year (2010), this collection contains all the Family Guy episodes currently available on DVD. Buying them separately, or from the USA, will not mean you will get more episodes.
In the UK, the seasons are incorrectly labeled; in the USA, the DVDs are sold in "volumes". In BOTH cases, the seasons are never complete. From season 4 onwards, the episodes are split incorrectly on the DVD releases; for example, the latest set, called "Family Guy Season 8" (Called "Volume 7" in the USA), actually contains episodes from broadcast seasons 6 and 7. That's right, you heard me. NO episodes from the actual season 8 are included, whether you live in the UK/USA/Austrailia/anywhere, it is irrelevant, because these episodes are simply not available.
So before you go slandering this box set, know that it contains every single episode of Family Guy currently available on DVD. You're NOT being ripped off by this seller. Fox are the one's ripping you off, by only putting 13/14 episodes on each "season"/"volume" release.