ebay (via Adorama) has a GoPro HERO4 Silver for $369.99 bundled with a massive accessory kit that includes a chest harness, head mount strap and what looks like a wrist strap, suction cup mount and bar/pole clamps, along with several other screws and adapters, among other items.
These are probably not official GoPro accessories, but as I pointed out in my recent 15 Essential GoPro Accessories post, you don’t always need the official GoPro gear to make things work. I just recommend going with GoPro batteries and chargers.
Even it was just the HERO4 Silver camera, it would still be $30 less than it sells for normally. The accessories, at this price, are just a bonus. Check it out here on ebay.