I use to collect coins as a kid and I'd have to say any coins that are different still catch my interest. It's a pretty simple and fun hobby/collection to do and you've set out how to start up also clear and simple. Especially as a child I think it's a good activity for them to do, stamps as well if they have people around them who use them, because they're items that atleast use to come by a person without having to buy for them, which makes them a somewhat easy to start of collection.