another set of suggestions by me
Expire Date
Most of event items are available through the year and most of them always will be sold in crucial moment.
Yes that's a good thing for hoarding and making zeny but the side effect could impact the zeny flow.
my suggestion is give some event/limited seasonal items an expiry date. after the expire date the item will be deleted or unusable.
the expiry date will last for 1 year or a month. this date is set after the last day of the event so people might still be able to hoard and sell at the last moment.
Honing Scrubs
there are some types of honing scrubs that needs some amount of zeny to reset a hone or free ones from IM.
my suggestion is make honing reset doable without using scrubs, in change the reset system will need some amount of zeny for a single gear and the price will keep increase up to 9999999 zeny
ex : Gear A with a bad hone 1st reset = 1000 zeny cost
Rehone Gear A
Gear A with a bad hone 2nd reset = 1050 zeny cost
Rehone Gear A
Gear A with a bad hone 3rd reset = 1125 zeny cost
and so on
this can be capped using the price or how many times a single gear was rehoned.
that when a honing scrubs came in
all honing scrubs require 0 zeny to reset the gear, but also refresh the amount of how many times a single gear was rehoned
ex 1 : Gear A after reaching 100000 zeny cost -> use Honing scrubs, hone is reset and the price back to 1000 zeny for the next hone
ex 2 : Gear A after reaching x times rehones -> use Honing scrubs, hone is reset and the amount of times is returned to 0 for the next hone
eventually all honing reset without scrubs will help the incurable zeny flow in ro2 back to normal again.
and the price can be changed at any moment.
this also opens up new event possibilities, like honing week or something where honing reset price is reduced and you can start selling Honing Scrubs again.