The only thing this game has of that nature is a GM trade. If you buy a piece of gear, a GM can trade it out for a piece that costs the same amount of the same type, eg. Eso pants of striking switched for Eso pants of maiming. However, this option is only available one time. Once you make one tradeout, you can never do another.

The idea of selling gear back to the vendor for a return of our tomes is a nice idea, but the weekly cap on tomestones is most likely a reason that it does not exist. Someone could cap on eso then want to sell a piece of gear, making them cheat out the weekly cap. Also, would selling eso pieces count towards that weeks cap? That would mean you actually earn less eso than people who don't sell their pieces. A few things to iron out to make this possible. Great idea and concept though