Also extremely easy to abuse the monster arena, there's only a few items you can get there that you can't get anywhere else (like some mirror accessories and a nu arcana) but it is great for getting powerful items early and getting copies of items you'd normally only get multiples of in a new game +
Can get prism specs, the elemental absorption plates, the 3 stat capsules, prism helms, prism dresses, haste helms, nova armor, moon armors, gold studs and others on tiers 5/6, and also easy to get weapon and armor you wouldn't normally have at that point in the game, though it makes it even easier.
The best items are still from the new dungeons though, but I think you can get multiples of some of those from the higher tiers in the arena, like the angel's tiaras, basically a haste helm plus prism helm (haste/status immunity) in one for the females.
