While I am glad that it will bring less store purchases in subsription game...
This will just make people in FCs or friends wire money thro paypal, steam wallet funds or (add some weird transfer sites here).
Dont think thats necessarily safer for consumer than buying from SE store, apart from steam wallet or paypal. But even then you are just gifting money that could be used for anything. And in this economy id use the money for food than mount. Cough.
So if you want the person to use that 20€ for mount, you just gotta trust it will be used for mount.
p.s. Lodestone already lists all mounts and minions available..so theres that..