You can get your own Asclarias, probably cheapest option. Alternatively you can get your own Mountain Gorilla on SI, you just have to kill 500 Mountain Gorillas, then the one you can tame will spawn, need to be level 18 I believe, to be able to tame it.
Sapphire Atrox, Gold Leprachaun, Lava Devil and Wasp Devil are just too rare, so not really an option.
S0ph1e was limited, so is going to be expensive. Oratan Axe was an Event prize and is very rare so is going to be the most expensive.
I think there's a new autoloot pet on Toulan but I'm not sure...