Pay for your inventory.

[Evergrey]

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I know I don't have much to say on this matter since I only have 2 jobs at 50 and don't craft except when I am bored, so I got plenty of free room.
But remember that this is a RPG game, and with all RPGs (I have played atleast) there are limitation to how much you can hold at once. We are given a choice on what we wanna keep and sell etc etc.

BTW, most event/season stuff can be bought by a vendor (as long as you finished it once). I have done so several times and sold on the market and earned myself a few GIL doing so.

And ofc I don't mean that you have to throw away EVERYTHING you have stored. But maybe sort out stuff you havn't used for a long time and perhaps sell it for a few GIL on the market. And if needed later on, buy some or gather it yourself.
Since the prices on the marker changes constantly you could sell something and later buy it much cheaper. I have done so many times aswell and earned more in the long run, itemwise and GILwise.