My advice is to go for the cheapest one. Most of them have the same features as the high-end ones, with some exceptions. Yeah, the more expensive ones might have some fantastic features, but trust me, you won't use them. You will only try them out a couple of times, and then you'll understand that it's not worth it and pretty much useless. If you want to get a good smart weight scale for your wife, go for the expensive ones, but in this case, trust me, you don't need an expensive one, it's not worth it.