I worry that'll happen and then the economy will shatter like how it did with the dice event :/ (of course I wasn't here when the emerald boxes came out so please feel free to correct me, but free rare stuff like that just doesn't seem to benefit the economy all too well....)
Well, the economy can swing in two ways. 1. In favor of the many 2. In favor of the privileged. I'm no socialist, but I really think event that appeal to the masses work best for the game as a whole. More people with better gear makes for a more enjoyable game! Also, you said the economy "crashed" in the dice event, when it really couldn't have been better. What you saw was a shift in resources. The economy didn't crash, it simply "moved". It shifted from being predominantly in the hands of a few toward being in the hands of the masses. Events like the dice event are precisely how an economy can be saved, not destroyed. An event that did crash the economy, however, was the first CWB event (the current one is doing the same thing). In the dice event, players simply allowed their galderrs and MS to change hands, but in the CWB, the money (if you're buying from item girl which I assume you are) disappears forever when it's given to item girl. With so many giving their money to item girl, the economy couldn't keep up. Galderrs simply weren't being "created" (that is, items being NPCed, galder drops from monsters being picked up, etc.) fast enough, and as a result, the economy swung in favor of galderrs as the main form of currency. That was the first time I think I've ever seen trickster's economy FAVOR galderrs over myshop points, since myshop points are almost always more valuable than galders.
An event like the sapphire box (the one Khloe suggested in te suggestions thread for March) is just what the economy needs so that it can stabilize.
I'm fully in support of an event similar to emerald boxes with keys drill able again. (If it's possible, I'd like to see them be "Sapphire" boxes instead of "Emerald Box No. 4", but it's fine if they are. Idc!)