Promotionnal items

[Arutan]

You're forgetting one of the biggest reasons the exclusives exist:

To encourage impulse buys.

If you offer something - ANYTHING - that, once past a certain point, will never be available again, you're going to get a certain percentage of buyers who, quite frankly, don't care about the item and may not even care about the limited-time extra, but is afraid that if they don't get it they might want it later but won't be able to get it.

It's a very, very effective tactic, and something that would be completely undermined if SE started providing other ways to get those extras later on. Suddenly these impulse buyers no longer feel the pressure. "If I don't buy it now," they reason, "I'll just need to wait a bit, and it'll come back. I can nab it then, if I still want it." This is not thinking that SE (or any seller, really) wants to encourage.

When a company provides a product, they want to move as much as possible of that product up front. Creating a product and having it sit around unpurchased in warehouses for who-knows how long is an expense, and they want to do as much as possible to minimize that expense.

You can take this in the other sens too. Lots of people would want the goods just for the in game item. But paying 35$-40$ and more for an in game item doesn't feel attractive, even though this price is for the goods. So they don't buy it.
Now, if you put only the in game item in the mog kiosk, for the same price or a bit higher than the other item from the same category, all those people would be more inclined to buy it, which at the end would represent a lot, taking into account that new people will be able to buy it too. It's a permanent gain that at some point will be higher than what the goods actually fetched for the game, considering that the good also have production costs, and sending costs.

[LineageRazor]

It's a permanent gain that at some point will be higher than what the goods actually fetched for the game, considering that the good also have production costs, and sending costs.

You could be right. I'm not a professional market researcher. However, I'm guessing that neither are you. SE, on the other hand, doubtless has actual professionals working on this very problem - and those professionals have advised SE to use this marketing strategy.

We can armchair about it all we like on the forums. It costs us nothing to do so. You can bet, though, that these professionals take their research very seriously, and while they may not always be right, their careers are on the line if they screw up too badly or too often! I'm willing to bet that SE has done the research, and decided that marketing these things as extras to other products is making the company more money that simply putting the extras up on the Mog Station would.