A few suggestions if you want to consider, based on recent price movements.
Salvation Run #1, Minor Key : 1st appearance of the prison planet Salvation.
Day Of Judgement #5, Minor Key : 1st Appearance of Spectre (Hal Jordan).
Given the amazing reception of Absolute Batman & continuing price increases, would you think that Absolute Batman #1 may warrant a major key entry (Premiere Issue)?
That’s all for now!