Hmm, let's see if this answers your question:
There are 3 methods of commerce in SWC.
1 - The NPC Shop system, present in most race starting cities that sells a very basic selection of items to new characters.
2 - The NPC Market system, accessed through specific facilities, sells the assets of dead characters and dissolved factions. Due to the pricing system, it is considerably lower than the player market, and is generally empty.
3 - The main source of trading in SWC is from other players and factions. There are the Commerce boards on the RPG Centre, a couple of IRC trading rooms, the Classifieds, and the Centrepoint Marketplace (CPM). There used to be other sites similar to CPM, but due to CPM popularity, and the exclusive nature of the market sites, they seem to have fallen out of use. All CPM actually does is make the process of finding a buyer for your goods easier and more convenient, it does not actually handle any of the other parts of the Trading process like makeover and payments.
Be wary of thieves/scammers - check out the Trader's Lounge on the RPG Centre for some good threads on how to avoid them. You might also reference the Guide - linked at the top of every page - which I believe has a section on Trading (in the FAQ if nothing else).
____________"May the Grace of Ara go with you, and His Vengeance be wrought upon your enemies."
Only fools and children dream of heroes.