There is a Southsea pirate town in eastern Tanaris. The place is called Lost Rigger Cove and you can get there by going throught a tunnel. The place is full of level 43-45 pirates who should be very easy to farm on high levels. These guys drop some nice silver, Mageweave and Silk Cloth and also have a good drop rates for blue/purple items for such a low level mob which makes grinding them worthwhile.