My philosophy is this: If I need it quickly, then only LBS will work. If I don't need it quickly, then I weigh out online price+shipping vs. LBS price plus sales tax. If they are within a couple %, I'll usually support the LBS.

It's really up to you and what you value. You could always ask the LBS to match, or at least come close to matching Jenson's price. You can also try SpinDoctor tools from Performance bike if you're looking for a cheaper price. There are times when the quality of Park Tools is warranted, but for other items, the cheaper SpinDoctor version is a smarter purchase for the home mechanic.