Michael Jackson's "Thriller" album from 1982 sold more copies than any other album in history, which is not good news if you're trying to sell one. Fine copies can be found at secondhand record stores for $3, while some people were asking $25 on eBay for an unopened copy in 2011. The most valuable copies are those that Jackson signed.
Check the condition of the record. It must have no scratches and must be in playable shape to interest a collector.
Check the label to verify the album is actually from Epic records. It should show QE 38112 on the label. The half-speed mastered edition should show HE 48112 and the year 1982.
Check for Jackson's handwritten signature anywhere on the label or the jacket, especially if you are not the original owner.