Earthbound was released for Wii U eShop. When it came out, we predicted Earthbound cartridge prices would decrease but not as significantly as other titles in similar circumstances.
How did we do? Spot on.
From the date of our prediction, the loose price decreased from $179 to $137 (-20%).
Some gamer's decided to buy the eShop version instead of the cartridge. So demand decreased a bit. There are lots of collectors out there who are willing to pay a premium for the original, which explains why prices didn't collapse.
This 20% decrease compares to a 40% decrease for Marvel vs Capcom 2 a year after its virtual release.