I'm glad I bought all the packs now as there are more tie-ins the more packs one has, even the Laundry pack has been useful for my family on Vacation.
All the builds provided by Maxis in Expansion and Game Packs are basic, (plus contents of that particular pack), to account for those who just have basic stuff and those people miss out on the tie-ins.
I wish Maxis could give instances of how the older packs have been affected and upgraded by newer ones. ie: Toddlers and pets going to the Jungle, building restaurants and shops there etc., etc.
PS: Those ceramic wall tiles and floors make beautiful kitchens, bathrooms back home!