From the Vault: Legends cards price Analysis

From the Vault: Legends Set average value

Set price evolution (paper):
Set price evolution (online):

From the Vault: Legends Mythics

Kiki-Jiki, Mirror Breaker Kiki-Jiki, Mirror Breaker
  Played in 274 decks in the last year
Progenitus Progenitus
  Played in 175 decks in the last year
Doran, the Siege Tower Doran, the Siege Tower
  Played in 27 decks in the last year
Captain Sisay Captain Sisay
  Played in 22 decks in the last year
Ulamog, the Infinite Gyre Ulamog, the Infinite Gyre
  Played in 19 decks in the last year
Mikaeus, the Lunarch Mikaeus, the Lunarch
  Played in 17 decks in the last year
Teferi, Mage of Zhalfir Teferi, Mage of Zhalfir
  Played in 10 decks in the last year