As one of its daily deals, CowBoom offers the used, second-generation Amazon Kindle Fire HD 7" 8GB WiFi Tablet
, model no. B00CU0NSCU, for $39.99
for shipping. That's $94 under the lowest total price we could find for a new one. (For further comparison, we saw a refurb for $65 two weeks ago.) It features a 1.5GHz dual-core processor, 7" 1280x800 IPS LCD, wifi, Dolby Digital Plus audio, Prime Instant Video, X-Ray for Music, X-Ray for Movies and TV, e-mail and calendar apps, and Fire OS 3.0 Mojito. Deal ends today.
Note that this model is in "fair" condition which may have some cosmetic imperfections; no warranty is included.