Beef in the U.K. is 'matured' (dry aging) by hanging for a period of 21-30 days at a minimum. Longer hanging improves the flavor and tenderness of the meat fibres.
In the U.S. the hanging process usually lasts about 14 days.
And while we're at it, the price of a roast joint of beef starts around $6/lb, so yes the cheapest cuts here are similar to prices in the U.S. from my recollection. The pricier cuts are aged longer, and would be abound $8/lb
