Connectify Dispatch lets you combine your WiFi connection, your Ethernet, your cell phone data connection and even 3G/4G dongles into a single internet connection with higher speeds and more reliability. The software allows you to select your primiary and secondary network, that means secondary will be used when primary fails. You can select your cheap WiFi as a primary connection and your costly dongle as a secondary internet connection. The software also automatically choose the most reliable connection available.
A video showing how Connectify Dispatch works
The Dispatch team also tested their product and tried to connect ten devices providing internet into a single computer. And the results were amazing. See the video below to get to know how well the software worked.