CharityDeductions is an organization that has assigned fair market values to items donated to charitable organizations. It includes values for clothing and various household goods. These are similar to the values given by the Salvation Army, but oftentimes the values assigned are higher.

These values have been tested in audits and have been upheld. I feel comfortable in recommending them for your use. There is a fee to using this software. The cost is $24.95 for one year or $19.95 if you purchase a two year subscription.