Power meter or TT bike?

I got a promotion at work, so I'm allowing myself a major bike-related purchase for next year. At first I was thinking of getting a TT bike so I can do stage races. Except there's (maybe) one stage race here I can compete in. Of course there are plenty of time trials, and TTs are good training. But if I'm going to drop over a grand to improve my training, wouldn't a power meter be the better tool? If anyone has one, was it a worthwhile investment? I'll be starting my 3rd year of bike racing, so I think I've reached the limit of improvement by the 'just ride your bike' method of training. Or maybe I should hire Smithers...