Myths
Myth #1
Myth #1 - the "Secret" Grinding Spot
"There are spots where the drop rate of cash or valuable items is much higher than other spots!" --- FALSE
Believe me, if there was such a spot, EVERYONE would know about it, especially the professional Gold Farmers. And what would happen next? Blizzard would 'nerf' it (they'd make it not as valuable). Blizzard strives to keep everything in balance. For example, grinding on mobs for cash and items will generally earn about 10 gold per hour (gph) at level 60. Certain areas MIGHT be better for you, depending on your class, but in general, it will be balanced across the realm. If they detect something out of balance, they WILL change the drop rate.
Case in point: After the 1.11 patch, mages were heading into Dire Maul, where the drop rate for Savage Fronds was pretty high. They were using AoE (area of effect) spells to kill bunches of mobs at once, getting a far greater number of Savage Fronds than could be gotten anywhere else, or by any other class. Within a few days the Dire Maul drop rate for Fronds had been reduced, to bring it in line with the rate in other places.
Another example is the Cemetary in Scarlet Monestary. I've seen gold-making guides that talk about all the silver and the blue items that the mobs there drop. "Kill them all, reset the instance, and do it again!". The mobs drop copper now, and nothing more.
FACT #1 - Blizzard keeps the gph rate balanced across the realms. It is something they totally control and do adjust.