It depends on you as a person. If you are a talented programmer, with a good portfolio, and can SELL YOURSELF. Then you can make a ton of money free lancing. I have friends that freelance and make twice as much as me working only 2 or 3 days a week. But if you don’t know how to sell yourself and get work freelancing is not going to make you a lot of money. You are not going to make huge amounts of money off craigslist or freelancing sites. You really need to have good clients who will get you more clients through word of mouth. I know I would make basically no money free lancing because I’m not great with people.
Try both see what works for you.