Craigslist is a gamble. There are many overpriced bicycles, in particular with any bike that is a well known brand. A four year old Surly LHT is not worth $1,000, for example. Hence, the same bike will be reposted several times over the course of months. My best scores from CL happened when I agreed to meet the person to look at the bike. I always try and lowball the price, but never over email or phone. That is too easy for them to be dismissive of my offer. Lowballing the price is easy to do if, in person, you mention that you have seen the bike posted for the past several months. Tell them their price is unfair, and that nobody will buy it. If they do not agree to the lowballed price in person, I have been successful at getting a friend to take a look at the bike (the seller doesn't know the connection) who purposely lowballs the price in person by 10% lower than my price. The seller doesn't sell to my friend, but instead calls me back to see if I am still interested in the bike...