Well, not necessarily.
I believe that Jagex stated some time last year or so that only ~6% of all players have over 1B, so assuming that this is true, then only a small portion of the community can afford even just a purple, although if you compare people who own blues/whites/crackers to them, there is a huge gap between them.
even so i dont have 1b anymore i still dont consider that rich. especially since gp is worth only half what it was just 2 years ago. purple will always get called poormans phat even if it is max cash. but who cares wear your favorite
Old School
I believe at one point that black santa hat and holly wreath were considered the "poor man's phat" since those are the closest head slot items to a partyhat, other than a third-age druidic wreath, but druidic isn't anywhere near as popular anymore.
tbh my fave rare is green h'ween. and that ones really cheap. its just really ugly for a forum avatar and doesnt look good with anything i ever wear lol. but its been my fav since i started playing
Old School