I shop Ebay and CL all the time. I do not even consider ones with "reserve" since I simply do not want to play the game.
My sewing machine I actually saw on Ebay first, and I contacted the seller, since she lived in the same city. I wanted to avoid shipping charges. She actually had it listed on CL as well. Luckily for me, she sold it to me, and its been a fantastic machine. It is just like new, and she basically had upgraded, which is what I am in the process of doing now. When I get ready to sell mine I will post it here, and on CL.
Bottom line is I think most folks just want to know, how much do you want for the item? If its in their budget they will bid, if not they will just keep on looking.
Shipping prices are so varied, its hard to say if they are padding those to get more money. I honestly look for "free shipping" most of the time. If its something I really want, like fabric : ) I will pay the shipping.
I think I have only given one bad review in the last 15yrs or so. That was because the person was misleading in his/her ad. The Header stated you would get "4 Pimatene Mist" and in the body of the ad it stated only 3. I unfortunately for me, did not read the body of the ad, and was suprised when I only received 3. I would have bid differently had I realized this.