With that pleasant thought, I decided to look at the preliminary ISK sales numbers I pulled from the publicly posted buyer reviews from Player Auctions. I won't have final numbers until 1 October, but the price numbers shouldn't vary much from the ones gathered so far.
Over the past 14 months I collected over 3400 ISK sales on Player Auctions from 123 sellers. Sometimes a graph is worth a thousand words, so I put together another one listing the average monthly sale price from July 2015 to August 2016.
The markets worked pretty much as expected through February. Then the price dropped on the secondary market while the price started rising greatly in The Forge through May. As far as I can figure out, the cause was the introduction of skill trading in February.
As far as I can tell, the huge demand for ISK in February was a direct result of players seeking to purchase skill injectors. That drove up the price of ISK on the primary market. But the prices did not rise on the black market. I think the first reason is that a few sellers migrated from various forums to Player Auctions. The types of sellers who hang out on forums are used to selling at much lower prices, so they served as an anchor to keep the regular crowd from raising their prices to match the price in Jita.
The second reason is a changing of one of the basic behaviors, at least where Player Auctions is concerned. Up until February, the primary and secondary RMT markets mirrored each other. When demand spiked in Jita, illicit ISK sellers would experience a similar rise in business. Player Auctions still sees rises, but the price drop in March coincided with the arrival of skill injectors for sale on PA. When the skill injectors became available on the market, the demand for ISK dropped off.
At the same time, however, players purchasing skill injectors without violating the EULA with cash were still purchasing their skill points by selling PLEX on the in-game market, thus driving up demand.
As the demand for skill injectors lessens, I expect a weaker relationship between the price of ISK in The Forge and that sold by illicit ISK sellers in the future. I do have to add that the hazard discount, the difference in price between ISK purchased in Jita and ISK purchased on the black market, returned to the $10-$12 USD range I had observed before PLEX broke the 1 billion ISK barrier last year. Last year, ISK sellers seemed unwilling to maintain that margin. Now, after operating with the lower profit margins for months, are the current operators willing to go lower? If the new wave of players decides they need to purchase illicit ISK, the ISK sellers could make up for the lower prices with higher volume. I guess we'll find out if that scenario plays out in a few months.