Btw, this system basically already exists for some content. Both of the HW Ex Primals drop a token for every player, 10 of which can be traded for one of the primal's weapons. So, you can either be lucky and have your weapon drop, or you just do the trial 10 times and go buy it. IMO there's no real reason not to implement this (or something similar) in general. It puts a definite cap on any gear grind, you can still get lucky, I see no real downsides (except "wah wah but *I* needed to do that dungeon a million times, why should others have it easier").

Also, there was another thread about basically a Glamour Log, which would work beautifully in conjunction with this.