Welcome back! Feel free to post or show some of the items in game and myself as well as others can help you put a price on things. Most greens are not worth much nowadays and some purples can be but the majority are not. PM me your IGN and I can help you out.
Location: I would never play off Occupy Wall St. for my guild name
Guild: We Are the 1 Percent
To answer your question plain and simple - prices and items are crazy wierd these days. If you have anything gold q8 or q7, it's probably pricey. Don't sell it to some lowlife kammadon person that wants to scam you out of a nice payday. Ask us here first in the price check section
some skins are in demand...others are meh at best. You could spend a bit of time looking thru past pc threads and see what others have posted (the past 2 years tops--before that it was a very different ballgame).
In general lower req and gold are usually more desirable than blue req 13 (usually I say here, because some skins--no mater what req are highly prized--see Voltaic spear, silverwing bows, etc).
Also look thru the wiki: http://wiki.guildwars.com/wiki/Main_Page
as some things you will find out for yourself...look at what drops from some dungeons (and ONLY drops from some dungeons), a common fire wand can drop from any foe in any chapter, while a Demoncrest Spear only drops from the frostmaw chest so its worth lots more.