You spend the money on the hardware capable of the higher spec though. The performance parts aren't free. They didn't reduce the price to match the spec.

Imagine getting a big 60' TV, but the screen is scaled to 48' if you don't pay a subscription. You still have a 60' TV, the manufacturer already paid for all 60' to be made. If they ask 48' TV prices, they're loosing a huge amount in upfront payment. In order to do that, they must expect subscription money to more than make up the difference. Since not everyone will get the subscription, that means the expected subscription money is close to or greater than the price of the entire TV, or the scaled TV isn't much cheaper than a normal 60' TV.

Also, because subscriptions are expected to pay for the extra pixels in all TVs, subscribers are paying the manufacturer to put disabled pixels in non-subscriber's TVs.