I wonder how much merchants make a day

You'r all wrong, and your therories too :P

Merchants are only the top of a GW Mafia, completed by:

Armor crafters, Xunlai Agents, Skill agents, Weapon Crafter and Consumables seller (maybe other NPC's are included)

They got about 12-20 slaves and they call them Henchmen!. They should pick up any loot they can from the players and give em to their masters if they dont want to be punished. Seriously, who would want to go to the hell (and beyond) to kill a overpowered monster and / or mobs for free? They must go or they would be.... tortured.

They also got money from:

Skill agent clients: they got about 1k for... teaching him/her another copy of the skill they developped. Too easy huh?

Consumables seller: umm they give ya drugs and they need materials..... Someone must find their secret lab.

Weapon Crafter: if they got 5k for any item created... ummmm they got so much cash in a day huh?

And... monsters... they have the weapons only because they are taugh to use em. They get em for free from the crap the merchants buy. Unique items are crafted by weapon crafters, dont hesitate this point :P.
Their gold drop is surely what they have stealed from the H&H that died in that battlefield .
And do you think that they learned theirselves the skill of letting te boss to look like being alone and then, spawn and kill you? Nah, that and their skills have been learned from a Skill agent!!.

Xunlai agents are only to keep their chest open for a little fee (50g and no month payments? mmm that smells bad). Maybe they spy us to tell the merchant to raise/lower the prices of something they need......

Scary......

lol nice topic

also don't forget that they do sell stuff, from keys/lockpicks to ID/salvage kits
which they buy back at half price, so they definitely are making some huge $$$ in the process

Anyone wanna try how many Gray dyes does the merchant in Ascalon have?

idk, i just had to make a post to show my uber avatar

They sell weapows back to foes...

Ohnoes ; blackmarket ftw ^^

So far ragnagard has the best idea ever, though I have another theory:

All weapons we consider "crap" (whites and stuff) are sold to the merchants, who then use their super secret time machine, warp to Pre-Searing, and sell them to noobs claiming they are "epic rare items".

Don't ask how Pre still has its own stable economy.

player kill monster-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->merch sell to monster-->monster got killed by player-->loot-->sell to merch-->..............