Using Values That Are Set For Cases In The Switch Operator

I am new to Java and I am trying to use values that are set for cases in the switch operator.

The first menu ask for you to pick a product and each product has a price on it.

The second menu ask you to pick a state with each state having a decimal value on it.

The third is asking you to put the number of cases and each case is 12 items.

A key note to remember is that each part that a person is choosing is on a different instance!

Here is an example of what i am trying to do.

Menu 1: I picked case 1 that is Computer and it is worth 1000
Menu 2: I picked case 1 that is CT and it's tax is 7.5

Third choice: I picked case 1 and that has 12 items

I want the subtotal witch is: (1000 * 12)

Subtotal in this situation is: 120000

Next i need the total value which is based on what state they picked for the tax percent value picked from the state menu case: (12000 * 0.075 + 120000)

Total value is: 129000

I will post the code I have but based on the choices a person makes will determine the values and I need those values set in the cases to put in a math equation. The problem I am having is retrieving these numbers form the cases inside the menu options and they are on a different instance. So How can I do this in Java code?

Here is the code:

This is menu 1

Java Code:

import java.util.*; //scanners and more
class menu{
public void display_menu() {
System.out.println ("Please select your product"); //Gives user direction
System.out.println ( "1)

[Code] .....