I agree with the addition of a high costing event reward item. Our event rewards are good as it is, when it comes to newer players trying to make their way to the top via collecting Event Coupons from Events and getting good beginner to intermediate items, but it lacks a high price items that is constantly sought out after, at all times. If the event rewards were to have this, I believe event coupons would regain their pull in the economy and be much more sought after and make event participation increase due to everyone's interest in attaining this high cost item.
As for the item's effect, I don't have an opinion on that as of right now.