true cost of a power meter setup?
For the Power tap setup you would need to lace the hub into a wheel of your choice. I'm not sure what that costs, but like you said, there is more involved than just the hub itself. You can lace it to a 404 or similar spoked race wheel, but then you don't have a training wheel that has a power meter. It comes with the computer interface (the yellow thing) and that is pretty much all you need. I think it comes with a HR strap also.
In my opinion, the Ergomo is a better option. It gathers power readings from the bottom bracket, so you don't need to worry about which wheels you are using. You can train and race on it. I think it is about $1,500, but that is the same as it would be for the Power Tap once you laced it to a wheel of your choice.
Rich Strauss, who posts on here, works with, nor for, but with Ergomo Power Meters. You should talk to him.

when i surf to Powertap, I just see the hub itself so I expect you need to build a wheel around it...are there other parts/pieces required? or altered processes that require additional cost? do you need a particular computer? do you race with power or go back to a race wheel?
i've read here on trifuel the value of a powermeter...i'm just wondering: what's the real item by item cost of a power meter setup?
(beginners want to know!)
thanks up front!
Tri-ac