Guild Wars 2

Create an item that is sold in the gem store, which allows you to unbind an item. (as long as it wasn’t originally soulbound/accountbound
Price around 3000 gems

I was just going to post a similar suggestion of something along the lines of an unbind stone so you can make soul bound items into account bound. So when you upgrade something such as an exotic item into an ascended one you can still have use for it on an alt. I have to argue that 3000 for it is a bit steep tho, none would buy it, I would say around 300-500 would be ok.