Well, the price of entry is pretty low. Can you afford a copy of "Planning Extreme Programming" by Beck and Fowler, and a stack of 3X5 cards?
The more I learn, the more I realize that the cards are far more powerful than any PM software I've used. Save the pennies (or $10,000 bills, if you have those to spend) you'd have spent on Microsoft or Rational software.
Should you invest in a paper company? No. I've also found that liberal use of the cards lowers the use of paper at the office. My data is anecdotal at best, but we avoid printing (and reprinting) requirements documents. Plus, the cards stuck up on a wall act as a progress chart for the release plan and the iteration plan. And since I insist that the chart be updated every day, people don't seem to mind sticking colored stickers onto a requirement card whenever it's done each day, rather than updating some file hidden away on the file server.
Read your PMP book (rather than memorizing it for the test), then read "Extreme Programming Explained." Huh. There's more PM in XP than in any $20,000 software package out there.
Finally, software doesn't manage projects. People manage projects. If you're still using terms like "resources" when you mean "people" then you may need to take a good hard look at your relationships with your people. XP is humanistic, which means your entire team has to behave like a community so that your best people don't leave.
Why all the free advice? Because I was in San Francisco while the dot-coms were sucking down the VC and then crashing prior to delivery. I watched a lot of money and talent get wasted, and I know why. "I'm mad as hell, and I'm not gonna take it anymore!" ;-)
Rob