Pay Zeny to extend Master Storage
I remember a while ago discussing with Kreuzbube the idea of adding a paid Master Storage extension. Since I haven't seen any comments on it, I decided to suggest it here. The basic idea would be to add an option where players can pay a sum of zeny to extend their Master Storage by 100 slots. Players could do this repeatedly until they're happy with their Master Storage size.
It'd act as both a zeny sink, which every server can use more of, and a quality-of-life improvement for players who decide to hoard items for future use, or older players who start stocking up on lots of different items/equipment.
It wouldn't give an advantage to wealthier players per se, since all it really does is make it easier to manage loot/storage. And newer players don't even have a need for it in the first place.
As it stands now, I know many players use one or more regular Storages to stock up on different things (personally my Master Storage sits permanently at over 650/700, while my main Merchant's storage sits at over 500/600 and a third Storage has over 100 items), so making it easier to manage our inventories would be very welcome. And it'll only become worse in the future when new maps, new loot, new equipment get added. Thus I'd like this to be seriously considered ASAP, assuming it's technically feasible.