I puchased a book for 3.00 and was charged 3.50 for postage in one order. In another order with a different seller, I bought 4 books for 8.00 with free shipping. Both Australian sellers. They were thick books and wouldnt go close to being large letters so I wonder if the sellers just made a mistake or whether there is something I am missing. Other sellers seem to charge very low postage rates for books and they must surely be losing money.

I thought books should go as parcel post.