I find parts like water pumps and master cylinders are easier to find and even cheaper than 10 years ago. Sure, the computers are not coughing out the parts like they should. It's the programming. Now there is a fine art to fooling the computer. Like those plug wires you wanted. I bet if you would have told them you had a 79 Trans Am with a V-8 you would have got your wires. When the parts come up obsolete ask the counter jockey to look in the book and find the part number. Then ask him to enter the number manually in the computer for availability. Chances are the warehouse has it.
Jim