Marriage for Sale

Today it was reported that an arranged marriage between and eight (yes that is not a typo) year old girl and 58 year old man has been annulled at the second time of asking http://www.guardian.co.uk/world/2009/may/01/saudi-arabian-child-marriage-annulled. The first time round the courts decided that she would have to sue for divorce when she was old enough
http://www.guardian.co.uk/world/2008/dec/23/saudi-arabia-human-rights.

What however is the source of our horror at this story? Is it the fact that she was 8, or the fact that her father could sell her? And suppose she were older, and (genuinely) consented - would that make it alright? And is this western cultural conditioning or something else?

There are enough Bible stories about dodgy marital practices (Punishment for rape, finding wives for Benjaminites) to make a simplistic reference to the Bible less than helpful. Yet if we take the theme of the New Testament: Love God and love your neighbour as yourself - and join that to the fact that God loves all his children - then for me the age is less of an issue than the selling - the treating of a human being as an object rather than a beloved child of God.