Luckapen via eBay offers this Lighter Spy Camcorder for $4.15 with free shipping. That's tied with our mention from two weeks ago and the lowest total price we've seen. (Outside of other eBay sellers, it's the best deal now by $3.) It features a 720x480 video resolution, microphone, rechargeable lithium battery, and USB.
Note: This item ships from Hong Kong and is expected to arrive in two to four weeks.