DirecTV's party line regurgitated perfectly, as fact. Just like how the airlines HAD to charge us extra for baggage because of the high cost of fuel but then, when fuel prices plummeted, surprise, surprise the baggage fees stayed, and even increased. Now, consumers just accept the extra cost and the airlines will continue to see how much nickel and dime-ing they can get away before people just stop flying. (Interestingly, studies have found that a $35 bag fee is acceptable, while charging $2 for a can of in-air soda is not. People are strange and/or stupid.)
Look, the reason DirecTV charges extra for these channels is because they can. It's not a service for those that only subscribe to SD. If they could charge an SD-only fee and they didn't think customers would revolt, they'd do that too.
It really has very little to do with the channels, or the cost to DirecTV to get them—it's a profit-motive, pure and simple. We, as subscribers, have allowed and accepted it. If, when they introduced these tier, subscribers had left, or even threatened to leave, in droves, they would have nixed the cost, ASAP. But, instead, enough ponied up ("it's just $5") and DirecTV adds another zero or two to their quarterly profits and they learn they can push customer's cost thresholds ever higher, incrementally, and it won't really effect their subscription rate. It's a win-win ... for DirecTV I mean. The consumers? Not so much.
It's $5 for a package of HD-only channels. Subscribe or don't subscribe. Pay or don't pay. They run their business the way they want to. Your only choices in the matter are which of their services you choose to subscribe to or whether or not you want to pay for their services at all. Business are in the business of making money...I guess that is a big shocker to you. Your contract is almost up either way. Good luck.