These goods are:
- Reins of the Crimson Deathcharger (~250k)
- Tabard of the Lightbringer (~150k)
- and around 100k in vanity items.
Here's a guide on how to do the line in the least amount of weeks possible:
Step 1. To start the questline, you need to have Friendly reputation with the Ashen Verdict on the toon you want to start it on. To do this, just kill the trash in ICC 25H before the first boss. Leave, rinse and repeat until you are friendly.
Step 2. Talk to Darion Mograine at the start of ICC to get the first quest. First, you'll need to find Light's Vengeance. This part is really easy and straightforward, just head to the location on the map and go through the little scenario. Next, you need some more items. 25x Primordial Saronite, which you can go buy on the AH for really cheap, and then 2 items from the ICC bosses Festergut and Rotface. These items will only drop in 25man difficulties, so make sure you aren't on 10 when you kill them. Go hand in the quest.
Step 3. You will get an axe, Shadow's Edge. You need to equip the axe and kill 50 trash mobs after absorbing their souls (there is an animation when you absorb the soul, so you can tell when you can kill them). After doing this, hand the quest in.
Step 4. For this part you need another player. At this point your lock should be up to Professor Putricide. What you need to do, is have someone AFK in the room with you. They don't need to do anything, they are only there so the boss doesn't reset. You need to attack Putricide once, but make sure you don't bring his health below 80% as this will trigger Phase 2. While he is Phase 1, you need to get him to place 3 slime puddles. One where he is originally spawned, one in the middle of the room and one near the door. Once he has placed the 3 slime puddles, get him below 80% hp and trigger Phase 2. While Phase 2 is beginning and he is casting, right click his table and drink the liquid. You will turn into another creature, with a new actionbar and new abilities. You need to use the ability that absorbs the slime puddles, and absorb all the slime from the puddles you placed around the room. The creature you are in will die quickly, so you need to do this fast. You can see your progress on the green bar to the right of your new actionbar. When it is full, use the Shadow's Edge ability on your new actionbar (it will be the furthest ability to the right, and won't be usable until the bar is full). If the cast completes before the mob dies, you have successfully infused Shadow's Edge and can kill the boss.
Step 5. Same as before, you need to have Shadow's Edge equipped. For the next quest, kill all the bosses up to Blood Queen Lana'thel. For this one you will need 3 players. You, a dummy, and anybody with a combat rez (dk, warlock, shaman, etc). The dummy players need to take off all of their gear. You need to attack the boss and get bitten. Eventually, you'll get another custom actionbar with a single ability. You need to use it on one of your dummy characters, and wait for them to die. Now, the next part depends on which combat rez you have. For this example, I'll use a soulstone from a warlock. The person who just died needs to use the soulstone to rez again, and then you need to bite them again when you get the buff, and wait for them to die again. After that, you need to bite the warlock, and wait for him to die. In total that should have been 4 bites (one on you, two on the dummy, one on the warlock). If this is the case, then nuke the boss and you are done.
Step 6. This one is really easy compared to Step 4 and Step 5. Same as before, you need to have Shadow's Edge equipped. You just need to stand in front of Sindragosa for 4 breaths, and then nuke her. Ezpz.
Step 7. Now, here's why it takes 2 months. You need to collect 50 Shadowfrost Shards which only drop from ICC bosses. To collect all 50, it takes around 8 runs (8 weeks).
Step 8. After you have all 50 shards, hand in the quest to get Shadowmourne, then go kill the Lich King with it equipped. He will drop an item called Sealed Chest which will start a quest. Go hand it in and receive the above listed items! You've just made 500k from a small amount of work per week (especially if you are already farming ICC for Invincible).
If you have multiple toons to do this on, you can collect a big payday in 2 months if you do the questlines all at once.