Here in Los Angeles and the surrounding areas, you can buy a USB wireless 4G stick from Clear or another wireless internet service provider for about $50. The monthly subscription for unlimited 4G wireless internet service is only $50 a month.
If you are willing to pay an extra $50 for wifi tether, you might as well just get a USB stick. It's easier than tethering. You won't have to go through some complicated setup or playing cat-and-mouth with MetroPCS. Just plug in the stick into a USB port, and you get unlimited internet, legally.