I do like buying fractionals from time to time. I can get them from my LCS for not too bad of a premium, and they are a cheaper purchase in absolute terms. I will occasionally get some online if the price is right or there is a cool design I want(like the MPM Egyptian half ounce rounds which are super cool!) Again, a way to scratch the itch for not much money, but certainly sometimes the premiums are just too much. I like the 1/2 Perth lunars also, and I don't have to sink as much money into the collection as I would if I collected the 1 ounce version. I don't buy 1 gram bars/rounds though, they are too small for me.
I don't buy them. Very,very occasionally I will be doing a trade at an LCS and have them give me a fractional piece back. I do have a bunch of fractionals set aside from a few years ago, so I see no need to get more. I agree with the comment about small denomination 90% being like a fractional.
A place here sell silver grams for $2.85 CAD. Some people just don't know how to cut their silver into smaller pieces. One ounce bars are perfect for bolt cutters. Some companies just prey on ignorance.