Best value for money on aero wheels I cycle to work three times a week over a distance of 13 miles in both directions. I do approximately 20mph most of the way there and back and I am looking for ways to speed up the commute.

Having read around the material online, it seems a decent set of wheels give the best performance increase per pound spent. 

So the question is what wheelset should I invest in? 

You can get models that claim to be Aero that range from a hundred pounds up to the low thousands. What would you recommend for a commuter?

A related but more searching question: would I even notice the difference at my level of performance?
Over a 40-minute ride, you may not notice much.

One older reference compares a then-standard 32-spoke 27" wheel to an aero rim with 28 bladed spokes, a high-end hub and an extra-lightweight tire. The estimated improvement over a one-hour time trial at 23mph was 44 seconds - an impressive improvement for racing, but not particularly meaningful for a commute. A more recent comparison by Rolf to the aerodynamic Mavic Ksyrium claims that their $2500 TT85 full-carbon disc wheelset saves 1 minute, 49 seconds over 40km.