I've posted bike stuff for sale on CL before (at reasonable prices)... Out of say 10 potential buyers, 5 of them will offer me a low-ball price (as in 1/2 or 1/4 of my reasonable asking price); 3 will pay for my asking price, but wants me to ship it to Nigeria; 2 will make a reasonable offer. I think sellers are used to inflating their asking prices so they can cater to these low-ballers. My experience is that most sellers on CL are willing to bargain a bit.

Another note is that the true bargains go very fast! You really have to monitor CL on a daily basis to spot the true bargains.