I dare to be controversial but post and packing are probably the best bargain on eBay!
I have just sold a small book for £8 with free post and packing. Ebay fee is £0.80, Paypal fee is £0.47, Postage (Royal Mail second class signed for) £2.64.
So far my net gain is £4.09. I forgot the cost of printing a label but I did use a second hand jiffy bag! Then there is the 9 mile round trip to my nearest Post Office where I queued for 25 minutes because I promised next day dispatch.
If time is money I am well out of pocket so forgive me if the next time it goes for recycling.
As a buyer If I find something on eBay from a trader I try and find their own website and buy off that. So I lose Nectar points but what the heck!