Pay for your inventory.

[raelgun]

Edit: Also, your point about them having a smaller playerbase is pretty moot. They also have a lower income, i.e. have less money for server and storage management.

And they pay for extra space from the pitiful amount they are given in the first place, the extra income that goes into pays for it, our sub is currently paying for the inventory we use as default and is already fulfilling its purpose for most its playerbase, the current inventory is actually enough for most people.
Most people do not kit out constantly all the jobs and have glamour sets for them, you are the one that has an issue with the games design approach which has given glamours a market and is a good thing really. Those that want to overuse the inventory space (which the default amount is actually a lot for most people even in the long term) should pay extra for it really, not every developer is a money maker like blizzard.

[Adire]

snip

Wrong. All of those games have decent storage space to start out with. Sufficient storage space is not gated behind payment, and even if it was (as may be the case in SWTOR later on), BUYING storage space is far more acceptable to me than renting it. Renting it is especially unacceptable to me when you are already paying every month. Also, our sub pays for many things. Inventory is one thing...but: When you're approaching an expansion, sure to fill the game with even more glamour, even more junk items that end up in your inventory after every other kill, even more job locked gear for each of the many combat, crafting, and gathering classes, you don't think that maybe it would be a good idea to divert some money to increasing inventory? That's pretty important you know...

But no, they are only devoting the needed inventory (and market domination capabilities) to those willing to shell out extra cash on their monthly sub fee. I highly doubt SE is doing that just to cover extra costs because they can't afford to give a free retainer. Remember, they are a business.

Also, where are you getting those numbers? I know a lot of people who do indeed kit out and gear every job they have at 50. The fact that you CAN do so, and are even encouraged to be versatile, means that the game should be designed to allow for it without causing massive inconvenience. SE even made lots of gear sets job exclusive instead of one size fits all or even role exclusive. I enjoy playing every role to some degree and have kitted them all out. My armory chest (and now inventory) are screaming in pain, why? Because I chose to do something that SE intended for us to do if we want to. And they have not provided something to deal with it sufficiently even though they have provided the system to cause the problem.

I really don't know how the glamour market is anything other than a crutch to help crafters produce end products that people will actually buy in bulk consistently at all levels. It's a bandaid for the crafting system's failure in that regard, and it's quite inconvenient to people who like to change their outfit occasionally.

Also, not sure why you keep bringing up Blizzard. Though last I checked, FFXIV was indeed one of the more successful MMOs on the market right now.