Honestly, the best option is to find a better Union. This kind of shit will only repeat every event. Try to see if you can get into top15-20 Unions of Experts once this event is over or something? Those ones should easily do 55m Union points in a single day.
And as said by others, brick is basically the only redemption here. Even Greed won't save you, since you'll still be lacking one copy from one weapon.I don't think that you're wrong, but we also have to remember that this is one brick vs. 3 bricks for a Grid that is starving for FLB weapons.
Saving up for triple-skill Hime weapon might be correct in the long, long, LONG term, but bricking this thing would last him a year. Or maybe two. Or maybe longer since it's Exceed.Dem four Gluttony Guns at slvl30 make for some fun. Too bad they're entirely unreliable, and those 30 skill levels would be so much better spent on basically anything else (that isn't Elaborate).