Power data is great. Both for motivation and training and just for the data. I was were you are about 2 years ago. I wanted power or a carbon wheel upgrade. I eventually came a cross a deal for a Powertap in a set of Reynolds carbon wheels. I jumped in with about the same entry price as you're looking at. If you are wanting to keep costs down look at the Powertap hubs and a rear wheel rebuild, the Stages power meters or look to see if a Power2Max meter could fit your bike. The P2Max was the one I chose until I saw the wheels. And unless you really need the independent left/right readings, the other solutions will be just fine. You will see a whole new world of info with real power data.