Maybe they don't have bosses or as many mobs in the area but they are less known so much easier to farm consistently AND SAFELY.
Each character may own an island but only after that character has been used to purchase at least 30 days of premium time.
Please read Can I turn off invitations to party, guild, trade and duels? Such a rare sight to see in the MMO world.
So, Black Market is where mobs get their loot, at the same time that it balances the internal economy of the game.
There are three different types which are green swamps Tier I-IV , red swamps Tier V-VI , and dead swamps Tier VII-VIII.
Decide which is the best and buy it.