The Burning Crusade Instance Old Hillsbrad: Durnholde Keep has a few notable items. If you are newer to WoW, you may not know these tips, or hell, you probably haven't even done the Caverns of Time: Durnholde or Dark Portal Instances.
Quick Aside: Inside the Caverns of Time instance The Dark Portal is THE BEST Spot for farming Netherweb Spider Silk, if you need those you can farm there solo and get tons, then reset the instance and farm away more.
Back to Durnholde Keep...
Inside the instance itself you are transformed into a human disguised player and can enter the old world version of Southshore. Inside the Inn there is a vendor named, Barkeep Kelly. Barkeep Kelly sells various alcohols, but she also sells Rumsey Rum Black Label for 2 silver each. Great little cheap way to get +15 sta for 15 minutes. This is a great cheap buff for PvP. yeah its only 15 stamina but for 2silver you can use one every rezz and not feel like your wasting your good buff foods.
Also inside CoT:OHB:DK is a vendor named, Thomas Yance - Travelling Salesman. Mr Yance sells noob starter clothings for vanity items, but he also is the ONLY vendor of the limited quantity (1) leather working Pattern: Riding Crop for 5g. Yeah the item it makes can only be used by level 70+, but is not usuable by Over level 70s. LOL.
But, at 5g it is well worth a flip to a leather worker.
And last, but definately not least, is the Aged Dalaran Wizard. He is a vendor that travels East to West along the road. As soon as you enter just go due East towards the road, once you hit the road follow it East until your path crosses his. Just look for his Dalaran Mage Outfit. He sells in limited quantity (1) Formula: Enchant Shield Intellect for only 6g. This pattern can be flipped for 60-80g each. Again this is the ONLY vendor that sells this formula.
So whether you are new or old to the game, remember to hit up CoT:OHB:DP, while you are in there area, for some easy flip items. Also any kills in the OHB or DP Instances will earn you reputation towards the Keepers of Time, which in turn will get your enchanter the +15 Agility to Gloves enchant once you reach Exhaulted. I predict this to be a huge profit and great seller once guild only BoA items are introduced in Cataclysm. This enchant was always looked for when twinking was viable and not hardly anyone had this enchant back then, and far far far less have it now.
Check out other BiS BoA enchant possibilities http://coldsgoldfactory.blogspot.com/2010/06/future-heirlooms.html"> HERE