Ocean Technology LLC via Amazon has UNITEK USB 3.0 4-Port High Speed Hub with BC 1.2 Charging for $3.49, you can save $4.5 with the code WDIE5BZU at checkout.

Features include:

• Compact size and portable, easily add 4 USB 3.0 ports to your Macbook, Laptop, ultrabook and tablet PC
• Enjoy data transfer rates of up to 5Gbps and spend less time syncing
• The extra Micro B power helps you to charge effectively for high-power devices
• Build in Overvoltage/Overcurrent/Leakage and Short-Circuit protection unit
• Designed with a built-in surge protector to keep your devices safe.