Craigslist is free. The only thing they charge for is "jobs" and "homes for sale", and I think that is only in certian cities. Craigslist is where you sell local, ebay is where you sell things you are going to mail.
The Craigslist scammers will offer to send you money and you send out a product in the mail, usually over sea. They send you too much, to cover shipping and then have you refund back the extra. the cretified check will bounce, after about 2 months and then the bank will pull the money back from your account. You loose your item, the shipping you paid and the money you sent the person as a refund. The only thing the scammers want is the refund.
I have both bought and sold thousands of dollars worth of stuff on Craigslist, I have never had an issue. But, I do it locally. It is not a good place to try to sell crafts, it is a good place to sell your used bicycle.