K2 Commerce via eBay offers the 6-Foot Waterproof USB Endoscope Camera for $6.28 plus 99 cents for shipping. That's tied with last week's mention and the lowest total price we could find by $4. It records at 640x480 at up to 30 fps.
Need a longer camera? e-Vipcom via eBay offers the 16-Foot Waterproof Endoscope USB Camera for $8.98 with free shipping. (Select 5M from the pull-down menu.) That's tied with our mention from last week and the lowest total price we could find now by $3. It also records at 640x480 at up to 30 fps.
Note that these items can take up to 8 weeks to arrive.