- Going into a town and seeing non-stop spamming of people trying to sell things just makes you turn off all your chats. It's impossible to read and it just becomes a bother.
- Instead of just selling things to NPCs, allow you to put your item up for auction. It becomes more of a motivation to actually want to go out and get good items/weapons instead of just getting one weapon for your class.
- I found that it is extremely hard to make enough money to buy really good weapons. With an auction house, prices fluctuate with the economies state (just like dye sellers do now) but more drastically.
Personally I think an auction house would be a great addition to GW. It doesn't have to be a big extravagant building (although that would be nice) and there doesn't have to be one in each town (although that would be nice too). Just a simple NPC that collects your items and puts them up for auction for the world to bid on.
