Abraham Z. |
If you are talking about for PFS, you need to have sufficient fame. Per the chart in the Guide to organized play, you need 13 Fame to buy an item 1600 gp (certain items are always available, regardless of fame, and you can always buy something that appears on a chronicle sheet, regardless of fame). If you average 4 fame/level you would be just over 4th level when you had 13 fame. If you got full prestige every adventure, you would be just over 3rd level.
Gallant Armor |
Level 3 to 4 if you are following the guideline that players shouldn't have more than half their wealth tied up in a single item. The only 2 Ioun stones I see at that price are +5 competence bonus on X Skill checks, –2 penalty to Y physical stat. For skill boosting items I wouldn't go above 10% of wealth so around level 6.