Depending on the character type, starting with an SoJ for 40 PGems is not the wisest thing. This is true, because you want a base for your equipment. If you have a duped SoJ, then you just traded away a bunch of your time for little to no reason, and you are set back by alot. If you trade them for something, say a Harlequin Crest Shako (+50% MF) or high rune (like, say, Vex), then you will either find it easier to get new Gems, or have a strong bartering item to use.

Naivete has nothing to do with the core of the situation.