A simple solution to the double meld relic fiasco is to have 2 paths:

1-You double meld a class weapon: people with gil or a vast collection of monkey paws and rabbit feet can go this route.

2-You obtain a U/U equivalent of the double melded weapon from either a quest, an NM, raid or a raid: this allows people with no gil or interest in gambling to still try for their relics. and put a limit on it where a person can only use this method only once. (if you're going 7/7 then god help you, start melding the remaining 6)

Happiness for everybody.