I put a load of old books on Amazon ages ago and intially I did reasonably well. It'd actually been about 18months since I took an active interest in what I had listed and I got an order out of the blue.
So having gone and posted the book I took a closer look at my account - Amazon charged me £1.60 to sell a book priced at £1.50 then allowed me the princelly sum of £2.80 for postage. Postage actually cost £3.00 so I'm down 30p before I even factor in envelopes and getting to the post office.
I'm aware this is a post office issue as much as an Amazon one, but I can't see how an individual can sell anything when competing with warehouses selling £0.01 books via discounted postal contracts