1200 Tickets - Orb of the Darkmoon

To get the 1200 tickets needed for this, you'll need to do 60 turnins at 20 tickets each.
It depends greatly on your server's economy on which way is cheapest... Typically it's dense stone, but sometimes it's thorium bars.
Here's a quick way to find out how much it's going to cost you per turnin:
Multiply the cost of one stack (20) of each item by the number of stacks per turnin: 2 for rugged leather, 1.6 for dense stone, and for the widgets, .9 * Thorium Bars + .3 * Runecloth.
Therefore, let's say that on your server, thorium bars cost 3g a stack, runecloth 1g, rugged leather 2g and dense stone 2g.
That means each turn in costs 3g for thorium, 4g for leather, and 3.2g for stone. (for a total of 180g for 1200)
Now you usually will end up using a combination, depending on what is on the AH at any given time, or your own farming skills, but this is a handy tool for those who plan on buying a majority of it.

After spending hours farming 125 of these based on this post and others here on wowhead I'm very sorry to say the info is no longer correct as of July 6, 2008. The Vibrant Plumes turn in became unavailable for me at 2750/3000. I was able to do 11 turn ins using a total of 55 plumes starting from 0/3000 rep. Do not waste your time or gold trying to get 125 of these you will only need 55 max. These are still probably the best way to get from 0/3000 to 2750/3000 and get 132 tickets and the Thousand Needles cave listed above is still the best place to farm them. Be wary of what you take as gosp

Correct me if I am wrong, but passive on-equip 22 spellpower is close to the max you can get in a neck item pre-BWL, no? I believe things like the Orb and other Epics have been put into the game to give solo-players and players not in a raiding guild something to work towards (and pay Blizz $$ in the process). For the effort involved (I got my tickets via Rugged Armor Kits, like most), this is not too bad an item for a dmg set.