If you're getting serious, but you're not yet sure just how serious you're going to get, the answer is yes, you can get by with Elements. For now.
Photoshop's "junior" version, Elements 5.0, is a great program. And it has a lot of the most commonly used Photoshop tools: the awesome Healing Brush and its cousin the Spot Healing Brush, the Magnetic Lasso, and the Clone Stamp.