In testing the inventory finished goods for a manufacturing client. I would like to know how to perform testing to get comfortable with both price and quantity of the inventory in a subledger file.

1. How does an auditor test thequantity? Please explain two directions of inventory test counts performed in a physical inventory observation, including which assertions they help to achieve/prove.
2. How does an auditor test theprice, what type of supporting documentation would an auditor request from a client to be able to perform such tests?
3. What other audit procedures besides price and quantity testing would help in testing for a valuation assertion?
4. Would any other Information be helpful in aiding the auditor during the audit of inventory?