This chart is Etze's math on why buying emeralds, and then opening chests is a better value than buying the skin for real money directly. I'll let him describe it;
Described by Etze:
I probably have to explain a little bit - this is web by the way. First column is the total amount of emeralds spent for one color of skin stones. Second column is the amount of skin stones you can get, third column is the amount of outland coins you can get. In the fourth column I summed those values up with a 50/50 rate of skin stones and outland coins and converted 5 outland coins to 1 skin stone. The next three columns are for all three skin stone colors simultaneously so nothing new there. Next next column is the ratio of emeralds spent to skin stones gained: column A divided by column D (or E divided by H for that matter) The last column shows how much skin stone you get per cash. I factored in VIP 13 (my level) and a 4x event. So for higher or lower VIP levels this changes. Then I compared this to buying a skin directly which equates to 5000 skin stones for the skin and another 3500 skin stones from the package. As I am playing in Europe the costs are in EUR and might differ for you. Bonuses for buying emeralds, opening chests or spending emeralds during events are not yet factored in.
It is clear though that the ratios are in favor of buying emeralds and buying chests. Do you agree?