@DuskyRose and Katsunami
Thanks for the explanations. I am seeing your point mostly. Shipping is higher in my experience in Canada but if I didn't prefer ebooks by far I would be giving the online trading a try.
Three years ago, I would lug home 30 books from the library, or thrift stores etc, without a thought, but the convenience of ebooks has totally won me over.
But I have some friends who prefer paper, so I will mention what you have told me to them