There's some nice random drops in the arena area, the problem is I don't think a 57 mage is going to be able to get past the gatekeeper mobs to get in there too easily.
If you could manage it...
https://wiki.project1999.com/Black_Bear_Pelt_Cloak
https://wiki.project1999.com/White_Bear_Pelt_Cloak
https://wiki.project1999.com/Silvery_Belt_of_Contention
Very rare drops but there's a chance and there's faction at the same time. Like with anything else though, things anywhere in Velious that are easily obtainable solo - the price just tails off.
The alternative is to join (or even start) the grind you see out in Wakening Lands at the Kael entrance sometimes, no notable XP but Netflix it up and send the pet in.