Trackman is certainly phenomenal. I had hit on it once before, mainly to look at my numbers with a 3-wood and learned a lot from it. The iron fitting I took I learned some more things...particularly that my angle of descent with my irons wasn't steep enough in accordance to Brian's 'Trackman Findings' post and it's no small wonder why I tend to hit the ball pretty high and now I know exactly how much more angle of descent I need.
That being said, in the times of this economy if your budget is really tight I'd probably suggest against it. The iron fitting alone cost me $150. The driver fitting is $100. The yardage gap fitting is $200. I'm not sure what other clubfitters with Trackman charge, but I'm betting it's a similar price.
I'm lucky enough where my budget isn't that tight, so I look at it like the charge was worth it for peace of mind. But in the end, I will say that the fitting w/Trackman produced the same result as the fitting w/o Trackman. With the driver, I think it would be a lot different because you have an angle of descent and some other factors to consider. Plus, w/Trackman you're hitting outside.
But again if you have a very tight budget, I'd suggest saving your money and put it towards Trackman's driver fitting or yardage gap work.
3JACK