BigDeals via eBay offers the Griffin Male-to-Male 6-Foot Auxiliary Cable, model no. GC17062, for $3.99 with free shipping. That's the lowest total price we could find by a buck. This cable is compatible with most AUX ports via the 3.5mm plugs.
Amazon offers Prime members the Etekcity 6.5-Foot HDMI Cable w/ Ethernet, model no. 025706346733, for $10.99. Coupon code "6FEET5OF" cuts it to $5.99. With free shipping, that's $9 off list and the lowest total price we could find. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $6.79.) It supports 3D video and 4K resolution and features gold plated connectors and a nylon braiding protection jacket.
Amazon offers Prime members the Pyramid 12 AWG Speaker Wire 50-foot Spool, model no. RSW1250, for $6.50 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $5.70.) That's the lowest total price we could find by $9. Please note that colors may vary.
Update: Note that this item is temporarily out of stock, but can still be ordered at this price for delivery when available.
Meritline offers the Merax 25-Foot HDMI Male-to-Male Cable for $6.99. Coupon code "MLCF04GN" cuts it to $4.99. With free shipping, that's a buck under our January mention and the lowest total price we could find for a 25-foot HDMI cable by $2. It features gold-plated connectors.