In a certain sense, good luck and bad luck are concepts defined by humans; they aren't that absolute.
One's good luck is the misfortune of one's adversary, and vice versa.
Items that can make their possessor lucky are extremely rare and naturally much sought after, and their rank is generally no lower than Tier Four. The market premium is almost excessively high, so in the absence of a talent upgrade, sacrificing them is hardly worthwhile.
Whether a short burst like a flood or a long trickle like a gentle stream is better, only time will tell.
But ominous items are different.
While equally rare and often effective over the long term, their uses are very limited. Generally, only a very few Spirit Beasts with cursing abilities and talents can utilize them. The management cost is also high, making them unsavory for sellers but not worth discarding, so they're relatively much cheaper.
