I have 60gigs a month which is a good amount. However, I have a few people that like to watch Netflix, youtube and do online gaming which eats it up! Is there a way to limit each IP address to a set amount?
Like the link provided by GabeU, there are quite a few routers out there that will allow you to throttle bandwidth (bandwidth control) per device IP. I've heard these TP-Link devices are pretty solid for home use:
Just make sure if you do the IP of the device, that you set it to static which is only good to use on desktops since people usually take laptops around to other places. It would be better if you can find a device that will do it by MAC address. Once the lease runs out on a dynamic IP address, that device may not get that same IP reassigned and therefore the rule will no longer apply to that device. Here is a video of how to set it on a TP Link device: