ICStation DIY Metal Detector Kit

Ordered two of these today on eBay from China - $3.10 total (free shipping). How is this possible? Eric Ostendorff (erco) led me astray once more!

Their website is here - http://www.icstation.com/

Edit: This video, (with a link to ebay) came up in a discussion with some friends on Facebook. Beau Schwabe posted his  BFO metal detector ... https://www.youtube.com/watch?v=ZO8bU6KtEk4