Hey, I was wondering about this for a while now. Some rewards in the strange stone shop seem out of place, like the number of stones you need were picked at random. I'll show a few examples.
As you can see, the prices appear random because the first two clothings are at 50 stones per frag, while the beach party is at 374 per frag. The Hebi frags cost slightly less than a single piece of a myoboku item. As well as, trumpets costing 10 stones more than Go Fuku clothing. If there is a way to fix this, then I'm sure most or all of us would like that. (This is a suggestion, so feel free to comment).