item "xxx" drops
item "xxx" goes for a price of 300
player "A" wants it and has 500 points available
player "B" also wants it, but only has 400 points available
player "A" wins item "xxx" for a price of 300 and now has 200 points available.
point pricing varies... but thats a pretty easy example of how a fixed price bidding system works.
most of the guilds from PoP era are either rebuilt with/without the same name, non active alt guilds, or just not around anymore. TR, Crimson Tempest, Triality, Triton, Cestus Dei... there's more, but those i remember off the top of my head as far as still actively raiding.