Powertap SL Zipp 808 - Complete System - Power Meters - Bikes :: all3sports :: Triathlon Bike Parts & Frames. If you actually have to know what the most incredibly expensive single components that are outrageously priced, then lust for this single wheel. It costs $1800 and is one of the fastest production rear wheels made, the Zipp 808 plus a Powertap SL power meter on the pack for measuring performance. These are time trail wheels, so best on flats.
For climbing wheels, Zipp makes the 303 (also with PowerTap). The wheelset overall is just 1543g, so its really light. I don't know how durable.
Zipp in fact offers the PowerTap SL on "all":http://www.zipp.com/products/wheels/powertap.shtml its wheelsets which is pretty cool.
The Powertap SL alone costs $1200. If that doesn't make you sweat, you can spend a cool $2,500 for a special crankset that also does power measurement made by SRM. Wow!