Where/what is the best place to sell used components

Selling low-dollar stuff is a pain.  Good packing materials and shipping are very expensive, not to mention the commissions on the auction sites. Then, people get it and they have buyers' remorse and want to return it, as if they bought from a store. It's not worth it, IMO.  I remember selling my father's old ESL tonearm that I described as a "rusty piece of junk" in my ad, but I was selling because it was rare and someone might want it to restore.  Don't think the buyer didn't complain because the plastic base was cracked or whatever.  Nowdays, I pretty much sell in person or keep it. 

Reading between the lines, it seems that you are still interested in audio (“my B&W’s”). So, if that is the case and since you are brand new to this site, the answer to your question is HERE, of course. What I would do is go to eBay and look at recent sales of the same items you want to sell. Since you are willing to consider the possibility that they may be “worthless”, which they are not, lower those eBay sold prices by, say, 25% or more and list them here accordingly. This way you can build positive feedback for yourself which will make future purchases and sales much easier. Even diehard Agon audiophiles are sometimes interested in buying inexpensive pieces for second or third systems, or as gifts; and most realize that everyone starts out with zero feedback. It’s up to you how you present yourself and the items in your ads here. Maybe even explain in the ad that one of your goals is to build positive feedback. If I were looking for inexpensive gear for my son, as I was a couple of years ago, I would have taken a chance on you 😊. Good luck.

The obvious answer is here, in Audiogon. 

As the others have recommended,, I would also try Craigslist for local potential buyers, as well as some of the Facebook buy / sell local groups.

I have successfully bought and sold used: McIntosh, Carver, Tandberg, Luxman, Denon, Yamaha, Onkyo, B&W, Klipsch, Mitsubishi, Technics, Fisher ...

Once you have photos and description, listing several places is easy.

listed/found/bought/sold on eBay (anticipate about 10% combined fees); slightly lower price (less fees, anticipate 4% PayPal seller's fee)) on usaudiomart, canuckaudiomart, reverb, craigslist, foreign sites.

some sites involve taxes, others don’t (helps buyers), and some, like eBay, add fees to the shipping cost (hurts sellers).

and as I am a member here now, I felt I should also list here. My latest, not what you think of as high falutin audiophile, (a piece I found/stated sounded great no matter it's cost) had multiple interest and sold here rather than the other sites.

IOW, don’t skip listing here as long as you have the photos and descriptions written.

returns: I offer unconditional returns, that helps me sell and get my asking prices. I don’t get returns, I wouldn’t sell/ship anything unless it was as described.