CowBoom offers the used 4th-generation Apple iPod touch 8GB MP3 Player in Black, model no. MC540LL/A, for $49.99 plus $5.24 for shipping. That's $10 below our used mention from last September and the lowest total price we've seen. (It's also $129 less than the best price we could find for a new unit.) It features a high-definition Retina Display, 3-axis gyro, front- and rear-facing cameras (the latter capable of HD recording), FaceTime, and Game Center.
Note: No warranty information is provided. This used unit may have dents or scratches.