So like if they made blanks that dropped that are trade-able, then a crafter can set it and trade it again and it binds once worn?

Technically you can, if you craft armor. You can sell that.
But if you're talking about costumes ... it would create a situation where people would buy the limited-time costumes for real money, specifically to resell for in-game gold. Then it could become a way to turn real money into gold, which is definitely not what ZOS wants.

It's not going to happen. As there are no style materials required, the only limiting factors for production would be either gold or the crown token if you don't want to pay gold.

So you'd have wealthy in-game players and wealthy out-of-game players fighting it out to control the market on outfits.

But more likely it would be thousands of unsellable basic outfits in guild kiosks and those wealthy players focusing on more premium styles which they could charge a lot more gold for. But demand would still quickly sink below the quantity supplied and it would wind up being a net loss system for most people.

I for one am glad ZOS didn't create a system that speculators could bubble and burst with real money.