Well... the thing that concerns me personally about series 5 is the fact that the label says there's 1 NPC in the pack. Assuming they literally mean 1 and only 1 like the previous sets, this is a problem because this set is 50% villagers and 50% NPCs. If you are in the US and getting the US packs that are 6 cards, you will get more villagers than NPCs and get more dupes of the villagers than the NPCs. This would also mean you'd have to buy a minimum of 24 packs for all 24 NPCs. Minimum, because this is assuming you get no NPC dupes (unlikely).
You might want to try to trade any dupes you get for other peoples' dupes, but keep in mind that it may be harder to trade for this set's NPCs because of them being rarer.