The Horse Breeder in Victory Park sells 6 mount skins for 2 platinum anniversary coins each.
The Fashion Designer in Yasker's Tower sells 14 costume masks for 1 silver anniversary coin each.
Are there any other vendors that sell items in exchange for anniversary coins?
yes, there are many ways to spend Anniversary Coins. They are for many kinds of events. For example the Class events, where you can Buy cosmetics at the Holiday Comitee Members, or the Anniversary Event and the Season Events, etc.
In-game: Poloo • Faction: League • Server: Evolution