Each of the different shops encodes a number in a different way, clued by the title. Using the five given clues, it is possible to figure out the encoding and the cost for the final item.
- APPETIZERS (First letter – A=1, B=2…): Antipasto = A = 1
- COMMUNICATIONS (Morse code – dot for i; dash for t): Civic Radio = … = S = 19
- BOOKS & LETTERS (Lengths of each word): A Newspaper = 19
- TREASURE HUNTERS (Position of the X in each item): Deluxe Shovel = 5
- CHEMICAL SUPPLIES (First letters of each word as element symbol, take atomic number): Carbon Atoms = Ca = 20
Translating the numbers to letters, using A=1, b=2, etc., gives the answer, ASSET.