Blame bots :| or either people making to much. I thought of this idea though Make a new character do leves i recommend something like crafting leves with 3/3 make hq stuff your gil gets doubled and just sell things on market place.
Buy on your alt, don't know if thats illegal or not but not like i'm botting just making alt and doing those things thought it help me to gain some gil and i do craft things on the side on my main sometime it will sit there for awhile until somebody wants to buy it.