I suggest that costumes should have required levels or required job class. According to my experience on the server, there are many novices and 1st job classes with high-end costumes(trending or the fancy/limited/unique ones).
This now depends on the GMs judgement for making required job classes such as Seraph wings should only be worn by 2nd job classes.
There should be appropriate costumes for novice and 1st job classes. Options are
Costumes that can be worn by:
1. All job classes
2. All job classes except novice
3. 2nd job class only (Fancy costumes which includes animated ones, e.g. Seraph costume, vicious, etc.).
For those players bragging their costumes using low level novices and 1st job class characters, they might affect incoming newbies joining the server because if a newbie plays on this server and see some novices equipped with seraph or other fancy costumes, then it might make some newbies feel envy, jealous, and discouraged that might affect RMS reviews.
I do not have problems with low profile players, I do admire them. If players wants to have a high profile character with trending costumes especially with unique animated effects, then they should use a high level character or 2nd job class.
EDIT: There are some players saying that there are many players on this server are rich. It may sound discouraging on incoming players and might affect reviews.