Increasing the cost of things that the top end players already have just hurts the players that are new... lol
Not a very good idea to do that
It would make more sellers vice buyers. Everyone on the server is a buyer at the moment, this includes people just joining. Hardly anyone is farming and selling the "must have" items such as SLS, or the lower tier essences. Increasing plat cost on the listed items would force people to farm and sell.
Another option is to completely revamp plat drops from qvic - T10 then do a server wide plat wipe.