Just for fun, I'm going to take a closer look at this within the profiles on Match.com. There is an optional question about salary, which I smartly did not answer.
I've had over 500 views of my own profile, so I am going to check out the age ranges of the "interested parties". It should prove to be fascinating, Captain.
UPDATE: I did a quick "back of the envelope" count of the number of guys who were looking for a woman more than 5 years younger than they listed themselves as being. No conclusive trend.U