Thankfully I'm never looking for one specific villager. Usually if I'm island hopping, I'm either just looking for someone cute that's not a specific personality type (because I already have two of them) or I'm looking for someone that fits the current or upcoming season. Like right now, if I were to go island hopping, I'd really be looking for a villager that fits the fall and Halloween times. But I already have Biff, who isn't perfect for fall but I think will look good with the fall colors anyway, Maple, and Wart Jr. So if anything, I'd really be hoping for somebody great for HALLOWEEN.
So far the highest amount of NMT I've used in one session is twenty-four, which I've actually done twice. The first time I went through that many I found Fang, my number one ultimate most loved villager ever. So that session was very well worth it. The second one I wound up taking Purrl, who I felt had a good enough look for Halloween.