I'm not sure what exactly to download but these are two addons that i would like to find.

1. one that displays co-ords in world map.

2. another that displays vendor sale prica and AH price when i hover over itms in my bags.

Any recomendations are greatly appreciated.

Back when I played WoW I used:

Auctioneer (it has tooltips for price information etc.. for items. but also useful for the AH)

http://wow.curse.com/downloads/wow-addons/details/auctioneer.aspx

Map Notes (Display your own marked locations on map)

http://wow.curse.com/downloads/wow-addons/details/map-notes-fans-update.aspx

QuestHelper (Display locations for quests on the map)

http://wow.curse.com/downloads/wow-addons/details/quest-helper.aspx

auctioneer for economic stuff and carbonite for everything else(quests,maps,npcs)

Two good world map coordinate addons:

WorldLoc (fairly new)

RiffCoords (old but clean and simple code, works well).