Values for guitars are available from secondary guitar marketplaces, such as Reverb and Vintage City Guitars, and value guides, such as the Blue Book of Guitar Values. The Blue Book guide requires the purchase of a book, CD-ROM or online subscription to access the values.

Reverb allows owners to sell their guitars and other music equipment directly to other musicians. A price guide search is available for electric and acoustic guitars. Price guide pages include an estimated value as well as a description, notable features and history of the instrument. Reverb's pricing guide is general and does not offer detailed pricing information for individual years or specific features that affect the value of the guitar.

Vintage City Guitars has been selling used guitars for over 30 years. They claim to pay 80 percent of the market value. Although the website does not offer a pricing guide, guitar owners can fill out an online form and attach a picture to receive a personalized value estimate, free of charge.

In addition to pricing guides, the value of a guitar can also be determined by current and past sales of the same item. Guitar owners can review websites that sell used guitars, such as Reverb, or check past auction sales on websites, such as eBay.