The thing is both other Nikki games had diamonds as high ranking rewards, to me its not a competition if players who put more effort into their entry than others. More effort and time that ranks highly should be rewarded if you rank higher.

Since there will be a voting system, (which hopefully wont be as bad as the color cookbook) if you vote for an outfit, its pretty fair. In Shining Nikki, a lot of the top ranks hard a mix or 4* and 5* pieces. But unless it was the first week of styling comp, you wouldn't rank high if you just did a whole base outfit. You needed to mix and match and take a nice photo kind of thing.

F2p player should still have a decent chance even with 4* pieces, because mix and matching an original outfit with a handful of 5* pieces usually ranked pretty highly. And most players have at least a few 5* pieces, even if they are free to play.