I would add some mounts that the taming items are cheap and easy to buy on market such as:
Pandas can be tamed using bamboo leaves and you can find for around 5k on market, depending on the world.
Bears can be tamed using a Slingshot and depending on the server it is around 30k.
Water Bufalos can be tamed using a Leech and it is around 20-30k on market.
Terror birds can be tamed using the Carrot on a stick item and price ranges from 20-30k aswell.
Not as cheap as the Donkey, but some cool mounts can be get with 30k!