As of June 2015, the average price of a 4-pound prime rib is $23.71. The Bureau of Labor Statistics lists this under the All Uncooked Beef Roasts category at $5.927 per pound.
A prime rib roast comes in a variety of grades. USDA Prime, Choice and Select are grading options. Prime is the highest grade, followed by Choice and then Select.
Most supermarkets carry the Choice grade prime rib for $9 to $11 per pound and the Select grade prime rib for $6 to $8. At retailers such as Costco, the bone-in Choice seasoned prime rib starts at $9.99 per pound, or $39.96 for a 4-pound roast. The bone-in Prime Seasoned prime rib starts at $16.99 per pound, or $67.96 for a 4-pound roast.