If you have the time and inclination, and a certain sense of daring, you can share your cellular data as a Wi-Fi signal for free, without connecting through your data carrier. I’m not a huge fan of jailbreaking, per se; even the non-jailbreaking solution seems a bit technical, and some folks might see it as borderline unethical.
If you fall into either camp, and want to set up your qualifying iOS device via your cellular data carrier, here’s how.