I got it free almost every year. And I got my Choice + local sports package (like CSN Bay Area type channels) for less than $100/mo. The key, most of the time, is that you have to threaten to quit, to get transferred to the retention department. I figured that out when they wouldn't budge on a discount or free ST once, and I literally was ready to cancel. Then, I never called to negotiate a price. Instead, I'd call in and immediately go to cancellation.
It also helps to always pay your bill on time. They kept calling me a Gold Star customer or somesuch, and when I asked what that was, they said it was because I was a long-time customer that always paid my bill on time. I asked if that was uncommon, and they replied that I'd be surprised.