As the National Standard Resource for used golf club values, the purpose of the PGA.com Value Guide is to serve as a resource for the value of "practical", used golf clubs in the secondary market, and not to serve as a resource for the value of collectible golf clubs. Practical used golf club models are bought and sold more regularly in the secondary market (typically for use), and therefore exhibit more statistically significant and less volatile fair market values. Golf club models that are classified as collectible may have been intentionally produced in low quantities or designed to commemorate an important event, person or accomplishment, both of which would inflate the demand price for the golf club model. These golf clubs may not be typically purchased for use. Also, some older golf clubs become more valuable as a result of their age, rarity or antique status. In these instances where golf club models are classified as collectible, the PGA.com Value Guide does not provide value statistics.