I wonder if Woolworth's Five and Dime charged more than a dime for it when new.
The Woolworth's in the "city" I (allegedly) "grew up" in, had a very few items that cost more than a dime, in the 1960's. AMT/Revel 1:24 and 1:25 scale model car kits were 2 bucks (everywhere that sold them). Even the tenderloin sandwiches, with onion rings or french fries on the side, (the deep fried breaded pork tenderloin was twice the size of a normal hamburger bun. Over-hung the bun by at least a inch, all the way around. Wish I could find tenderloin sandwiches like now-a-days.

) banana splits, malts, and shakes at the soda fountain were a buck or a little more. A 9 transistor AM pocket radio was a buck anna half, with a Ray-O-Vac 9 volt battery, new canvas tenny sneakers was 3 to 5 bucks, depending on brand .... I think mum paid 15 or 20 cents for her L&M's (single packs) .... I think I paid 30 or 40 cents for a box of 50 Federal .22 LR. ... (the YMCA across the street from Woolworth's had a 20 or 30 yard range in the basement.)
Polancic’s in Ottawa, Illinois sells tenderloins like you describe. I get one in a hot plate(open face sandwich) with mashed potatoes and gravy from Illini Lounge in Marseilles, Illinois all the time.