I think the question that determines what software you need is, "How much, and what kind, of editing do I want to be able to do?"
If all you want/need to do with your photo's is correct exposure a couple stops either way, correct basic color imbalances, crop, sharpen and re-size then there's really no reason to invest in Photoshop or Elements or Lightroom. There are several applications that will do all of that, and a whole lot more, for free. Once those products no longer do what you need, THEN it's time to start asking about more professional strength applications. But those professional strength applications are for those who want/need to establish a workflow.
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