How can i make this into a menu where you select a letter and you get a response that reads

you have choosen "a" which is $2.50


/* SIUE's bookstore is having aspecail sale on tiems embossed with the cougar logo. For a limited time, three items, mugs, teeshirts, and pens
are offered at a reduced rate with tax included to simplify the sales. Mugs are going for $2.50, teeshirts for $9.50 and pens for 75
cents. Coincidentally, your parents (or spouse, friend, coworker, or other person you know off-campus) just gave you $30.00 to buy SIUE
stuff for them.*/

#include<iostream>
using namespace std;
int main()
{
char symb,symb1, symb2, symb3;
int item_purch, numb_item_purch, quit;
double mug, teeshirt, pen, tot_mon, curr_cash, mon_spent;

cout << "What do you want to buy today?\n";



cout << " A) Mugs $2.50 " << endl;
cout << " B) teeshirt $9.50 " << endl;
cout << " C) Pens .75 cents " << endl;
cout << " D) Quit" << endl;
cout << " Enter your letter and press Return when finished" << endl;
cin >> mug;
cin >> teeshirt;
cin >> pen;
cin >> quit;
mug = ('A' || 'a');
teeshirt = ('B' || 'b');
pen = ('C' || 'c');
{
if ((mug == 'A') || (mug == 'a'))
{

mug = 2.50;
}
else if ((teeshirt == 'B') || (teeshirt == 'b'))
{

teeshirt = ('B' || 'b');
}
else
{
cout << "Wrong select a letter" << endl;
}
}
cout.setf(ios::fixed);
cout.setf(ios::showpoint);
cout.precision(2);

switch (symb)
{
case 'A':
cout << " A) Mugs $2.50 ";
mug = 2.50;
break;
case 'B':
cout << " B) teeshirt $9.50 ";
teeshirt = 9.50;
break;
case 'C':
cout << " C) Pens .75 cents ";
pen = .75;
break;
case 'D':
cout << " D) Quit" << endl;
quit = 0;
break;
}



return 0;
}