Actual Value of Little Legends & Suggestion for a Tweak
How much is a Little Legend actually worth? No, this isn't a philosophical question. Based on the pricing system that Riot has set up we can calculate the value of each Little Legend.
First, we start with the overall value of an entire series. There are 54 possible results from an egg (3 Legendaries, 6 Epics, 9 Rares, 3 levels each), and each time you get a result, you can't get it again. That means in order to purchase an entire series, you would need to purchase exactly 54 eggs. Since you can buy bundles of 11 eggs at a time for 4900 RP, that means you'd need 5 bundles (24,500 RP, 55 eggs) to complete a series. You'd end up with an extra egg from this.
Second, we need to understand the proportional value of a Rare, an Epic, and a Legendary. To find that, we need to do some basic Algebra based on the rarity of each.
Rarity: Rare = 75% Epic = 20% Legendary = 5%
In other words, a Rare is 3.75 (75/20) more likely than an Epic and 15 times (75/5) more likely than a Rare. Now we'll apply those proportions to the total cost we found earlier:
24500 = Legendary (L) + Epic (E) + Rare (R) 24500 = L + E + R 24500 = 15R + 3.75R + R R = 24500/19.75
R = 1240 E = 4650 L = 18600
That gives us the values for the groups. Now we need to break it down into each individual egg by dividing the value of the group by the number of eggs in the group.
Egg(R) = 1240/27 = 46 Egg(E) = 4650/18 = 258 Egg(L) = 18600/9 = 2067
Thus, the estimated value of the very first egg you purchase is about 190 RP (.75x46+.20x258+.05x2067), and this value continues to grow as you purchase more eggs and remove more Rares and Epics from the pool.
There's a lot of heartburn around the pricing structure, and people are complaining that getting the one Little Legend they want is far too costly. Most likely the pricing scheme was chosen to keep the Legendary Little Legends feeling... Legendary, but it seems to have had the adverse affect of turning off people who might have been willing to purchase something, but not quite that much of something.
Compromise: I'd recommend Riot allow for the purchase of Rare Little Legends directly at double the value of the first egg, 380 RP, and Epic Little Legends directly at 4 times the value of the first egg, or 760 RP, while keeping Legendaries available only through the random eggs. This will give an avenue for those who don't want to collect an entire series to purchase what they want at a significant premium while keeping the rarity of Legendaries intact, which is where most of the value lies anyways.