Hi,
Kenji Alt has an article on Serious Eats which talks about this wonderful cut at a cost of $99.
Link to the Tastiest Cut on the CowlActually, this steak does not have to be expensive. The solution comes when you are purchasing your rib roast for a special occasion. For years we have read about the purchasing the small end of a rib roast. There is less fat and it cooks more evenly.

But, if you purchase a large end of the rib roast, it comes with a nice cap steak at no extra cost.

Yes, it is easy to remove. In fact, you may remove it and dry-age the remaining roast for a period of days or weeks. That cap steak will be delicious.
Tim