I have two
but I have no idea where to sell them. I know the price for sale which is $600. Adorama, B&H, and KEH seem to charge much lesser than any other used lenses. I got no responds from CL and Facebook for few weeks. Any ideas?
You as a private party cannot get the same price as KEH, B&H and so on. You will have to possible at 2/3 of their asking price or as you have found the equipment will not sell.
I have sold maybe $2K worth of photo equipment in the last 18 months. Some stuff that is in high demand goes to eBay. The way to get higher p[rices on eBay is to (1) have lots of very good quality high resolution pictures and describe in great detail and tell the history off the thing. Buyer want to reduce risk and know more up front. Error on the side of giving to much info. Then if it is a low demand lens or body KEH will usually pay you at least some minimum amount. They pay low but they are VERY easy to sell to. They pay shipping for ANYTHING.
CL is not very effective because only local see it. eBay lets you sell world wide. I've shipped stuff to Europe, japan, australia and china. People from all over the world saw my eBay add for a Nikon F2 or the Bolex 16mm camera
I do use CL for objects that have low value and are expensive to ship and I don't care much how much I get. For example I sold a bundle of very old studio light stands on CL. But I sold name brand stands for $15 each.
For setting price the BEST place is to do an "advanced" search on eBay and look at COMPLETED listing. These will tell you the price the item actually sold for, not the asking price. I looked for your lens and the only ones the sold for $600 were new in the box, you will have a better chance of selling it for mid $400's. Like I said 2/3 of KEH's selling price