Accurate as of May 2013
Aegis of the Legion is a very cost-effective item, and it now upgrades into Runic Bulwark, which is slightly less cost-effective, but provides more statistics. For just the item owner, with the aura hitting no allies, Aegis is 107.32% gold efficient, and Bulwark is 96.56% gold efficient
.
Below is the math, in terms of gold efficiency. I've used the cheapest items available for each statistic to calculate the equivalent gold value of the final item. Obviously if you're comparing against more expensive (and usually more efficient) items, the gold efficiency of the Aegis and Bulwark will fall.
100% gold efficiency means the item is granting as many stat points as if you had spent the same gold on the raw stat items; A higher gold efficiency means you're getting more stat points.
As for the stacking portion of your question, its best handled in a separate question. The short version: If you own the item, you can have double auras, no more; everybody else gets a single aura.
Gold Equivalencies
- Rejuvenation Bead (180g) = 5 health regen; 180/5 =
36 gold per 1 health regen
- Cloth Armor (300g) = 15 armor; 300/15 =
20 gold per 1 armor
- Null-Magic Mantle (400g) = 20 magic resistance; 400/20 =
20 gold per 1 magic resistance
- Ruby Crystal (475g) = 180 health; 475/180 =
2.63889 gold per 1 health
Item
250 health, 20 armor, 20 magic resistance
250 * 2.63889 + 20 * 20 + 20 * 20 = 660 + 400 + 400 = 1460g worth of stats
Aura
10 armor, 15 magic resistance, 10 health regen
10*20 + 15*20 + 10*36 = 200 + 300 + 360 = 860g worth of stats
Now, if the aura hits 1-5 champions:
1460g + 860g * 1 = 2320g worth of stats for 1 champion, 107.32% efficient
1460g + 860g * 2 = 3180g worth of stats for 2 champions, 147.91% efficient
1460g + 860g * 3 = 4040g worth of stats for 3 champions, 187.91% efficient
1460g + 860g * 4 = 4900g worth of stats for 4 champions, 227.91% efficient
1460g + 860g * 5 = 5760g worth of stats for 5 champions, 267.91% efficient
The item's total cost is 2150g, so the item is gold efficient for just the item owner.
Item
300 health, 20 armor, 20 magic resistance
300 * 2.63889 + 20 * 20 + 30 * 20 = 792 + 400 + 600 = 1792g worth of stats
Aura
10 armor, 25 magic resistance, 10 health regen
10*20 + 25*20 + 10*36 = 200 + 500 + 360 = 1060g worth of stats
Now, if the aura hits 1-5 champions:
1460g + 860g * 1 = 2852g worth of stats for 1 champion, 96.56% efficient
1460g + 860g * 2 = 3912g worth of stats for 2 champions, 133.73% efficient
1460g + 860g * 3 = 4972g worth of stats for 3 champions, 170.90% efficient
1460g + 860g * 4 = 6032g worth of stats for 4 champions, 208.06% efficient
1460g + 860g * 5 = 7092g worth of stats for 5 champions, 245.23% efficient
The item's total cost is 2950g, so the item is 96.56% gold efficient for just the item owner, and is fully gold efficient if the aura is on at least one ally champion.
Best Answer
So I did some informal testing, with probably a large margin of error, I have some pictographical results.
I picked Blitzcrank, because I own him(it?) and he has a base 300 ms. 8 Seconds of walking down the bottom lane put me a little ways behind of the inhibitor.
Purchasing boots of speed boosted him up to 350 ms, and 8 seconds brought him past the inhibitor, put not yet past the inhibitor turret.
I attempted to record results for 406 and 455 (like I said, it's hard to get the higher numbers precisely) but botched the results, and in each case I was only about the same spot as 350 ms.
Finally, I bought Phantom Dancer and Boots 5, hit ghost (un-talented, sadly) and activated rank-5 overdrive to see how far I could get when speed was pushed to egregious levels. Since Overdrive lasts for 8 seconds, it made for a far more accurate timestop. I made it here.
So we can safely conclude that, unless you're backed in to your own base, it is always faster to recall.
Now if you'll excuse me, I'm going to go avenge my horrendous
6 - 4
previous test game. I will get Ashe Bot this time. grumble grumble