Why does i5 2500k cost so much more ?

Solution
Because they're old architectures which were sold years ago and are discontinued.
Retailers are going to do one of three things; set their prices higher, as people who want to upgrade from say an i3 2100 to a 2500k will generally happily pay a bigger than normal amount for the upgrade or buy used.
The other two things they'll do are leave their prices stagnant or change based on market conditions until they have no stock left, then they become ancient, and people think that meas they're 'vintage' so they sell for stupid high prices.
Because they're old architectures which were sold years ago and are discontinued.
Retailers are going to do one of three things; set their prices higher, as people who want to upgrade from say an i3 2100 to a 2500k will generally happily pay a bigger than normal amount for the upgrade or buy used.
The other two things they'll do are leave their prices stagnant or change based on market conditions until they have no stock left, then they become ancient, and people think that meas they're 'vintage' so they sell for stupid high prices.
 
Solution