There are a few factors that contribute to the value of this guitar, including:
Year of Production: The 1981 Alvarez Yairi series is considered to be a highly desirable vintage model, with many vintage guitar collectors specifically seeking these models out.
Condition: The overall condition of the guitar plays a significant role in determining its value. Guitars in excellent condition with minimal wear and tear command higher prices than those with significant damage or repairs.
Playability: The guitar's playability and sound quality also impact its value. A guitar that is well-maintained and has good action, intonation, and tone will be more valuable than one with playability issues.
Rarity: The Alvarez Yairi DY53 is a relatively rare model, which adds to its desirability and value.
Given these factors, the estimated market value of a 1981 Alvarez Yairi DY53 silver harp acoustic guitar in excellent condition is between $2,000 to $3,000.