Appraisers
All antiquities collectors specialize in specific collectibles. Music box appraisers are knowledgeable about the history that made music boxes popular in through the 1800s, the original manufacturers and the evolution of music boxes. For determining authenticity, Musical Box Society International says "appraisal requires a hands-on examination." They also keep up to date with the trends. By the time a valuation book is printed and published, there could have been significant increases or decreases in demand for a particular box.
Rarity and Age
Although music boxes are still being created today, the music boxes that are older than 50 to 100 years are often more valuable. This also has to do with available supply. Over time, treasures are lost or destroyed. In some cases rarity is more important than age If there are 50 music boxes from the manufacturer Ducommun made in 1865, but only five by the manufacturer Automata from 1890, the more rare box may be more valuable even though it's not as old.
Desirability
High demand increases price for rare music boxes. Dr Lori says that a strategy to gain interest in an antique music box is to get people talking about it in respected publications. She says another level of desirability is "an object with a pedigree (a piece acquired from a major collector or a celebrity), a strong provenance, or an impressive exhibition record derived from the work's inclusion in major museum shows and gallery exhibitions."
Condition
Like cars, antique music boxes are valued by their condition. A car with dents, scratches and engine problems will be less valuable than one without a scratch. The closer to the original manufacturers production it is the more valuable the piece is. Even restoration and repairs can devalue the music box.
IRS Requirements
The IRS requires that a certified appraiser perform the appraisal of your antique music box if you want to claim a deduction. This is usually necessary when claiming donations for property give to a charity or museum. The IRS determines that "if the claimed deduction for an item or group of similar items of donated property is more than $5,000, you must get a qualified appraisal made by a qualified appraiser"