Now that the Iron Banner has been available in Destiny for three days, players are starting to hit Rank 3. And as a result, we're getting more details regarding how the reward system functions.
For starters, we now know that it takes 2,400 Iron Banner reputation to increase from Rank 2 to Rank 3 (the maximum ranking). It takes 100 to get to Rank 1 and 1,200 to get to Rank 2. Unfortunately, there's little motivation to grind to Rank 3 since it's now confirmed that Lord Saladin, the Iron Banner vendor, sells no new gear at the max level. Basically, what you see right now is all you'll be able to buy from him, regardless of your rank.
So then how do you get all of the gear promised as rewards for participating in the Iron Banner?
According to multiple players, once you hit Rank 2, you gain the chance of getting the Legendary items to drop when you complete Iron Banner matches. So basically, if you want the entire set of gear or a specific weapon, you need to grind Iron Banner Crucible matches and pray to the RNG Gods. It's also worth noting that duplicate items have a chance to drop and, like the gear from the Queen's Wrath, it can not be salvaged into Ascendant Energy or Ascendant Shards.
As a reminder, you can earn Iron Banner reputation in two ways: completing those ridiculous bounties, or winning Iron Banner matches. If you lose a match, you gain no Iron Banner reputation, although you still get your standard Crucible rep and marks. Unlocking and equipping Iron Banner items and gear will increase the amount of Iron Banner reputation you can earn.
The Iron Banner event is just a week-long and is set to end on October 14. It's assumed that the event will return at some point in the future, and you're reputation will remain as is.