I've brewed from extract and its turned out great. I haven't used an actual 'kit' though. I started by showing up at my LHBS and asking them what to get and they put together all the various ingredients and instructions on what to do. Was this more expensive than an on-line kit? Most likely. But the great part about going the brick-and-mortar route is that the store owner is a brewer with a vested interest in my beer turning out well. Every time I go in, my LHBS guys even remind me that if I have any questions, to call them so they can help troubleshoot. Capitalism at its finest..
So, if you have the option in your area, I encourage you to support your LHBS. The owner will most likely be happy to give you advice so your beer turns out well, so you come back and buy more stuff. Call me old fashioned, but I really like the brick-and-mortar experience and the ability to talk with the live humans instead of ordering in-line. Forums like this are great, but a face-to-face conversation with an experienced brewer can make a world of difference.