A gold sink everyone would want, more spends alot vanities. We have a 10m and a 25m but I am sure just about every person who has made 100m+ has bought 1 spends a lot vanity or all of his vanities. Add a 50mil and a 100m vanity to him, if they look good enough then I am sure they will sell out 10bil worth on the first day. What about those video elixirs we are limited to? Give people 3 options, 100k/150k gold, video, or plat option. Adding this would make a big difference in pve because during gates and swamp temple we are limited on time and those videos take 55-75 seconds just to watch. Add locked chests that have a good drop rate on items that costs 1m to open and gives 3 random items which changes the contents monthly.
Add the gold cap of 999m and add more gold sinks to keep a stabilized economy.