Well if you look on a job site its not hard to find a listing for a Database Programmer at $140 an hour. Thats not entirely purely webdesign though.
I worked for a brief period of time as a contractor through this "frontpage" webdesign company. They demanded all the people use frontpage to make sites (I think because the boss was stupid and thats all he knew so he needed to be able to edit the sites himself) Anyways they didn't have anyone who could code or program, and they needed someone, so I did 1 perl script for them, took me 5 hours, got paid $500 and then left cause they wanted me to use frontpage. But they paid their web designers (now this is small time if you just know frontpage) $10 an hour.
Right now I'm going to school and working, I make around $100 an hour+ but its not full time. If it eventually becomes fulltime I'll be making quite a bit though. Another good source of income for us independent people is to start a hosting company by being a reseller for another one. I "host" all the sites I make and I take a $25 a month profit off each. Not much by itself but after 10 sites thats $250 a month, which is near my rent, after 20 sites thats an extra 6 grand a year, and so on.