You should make an experiment to figure this question out by taking a number of volunteer test subjects, designating one group of people as possessions of another group, and document the prices at which the ruling class buys and sells the lesser volunteers.
Then simply rename it slavery.
Otherwise people can't be bought or sold, although I'd gladly change my mind on the subject if you gave me a dollar.
None.
Humans are probably worth as much as a women's 9-month salary, the baby is growing in the mom's stomach for 9 months '_' .
A human life has infinite worth, because humans have virtually unlimited potential.
None.
A little Asian kid is worth: $3,026,676 (thats me)
The price of a person is judged not by what their values are, but how they honour their values.
Thus, if a person values their computer, they are worth nothing. But if a person has a sense of respect and reputation, they are worth a whole lot more.
A person may go so far, before a value is a crime. According to laws, a person is worth too much that in essence, they are invaluable or infinite. A person is not infinite. They are worth their moral values. They are not worth their style, but rather their integrity.
None.
Considering there are roughly 6 billion people on the planet, and we know of no other sentient species (maybe dolphins or monkeys but w/e) and we own everything, each person is worth exactly 1/(6billion) universes.
None.