Also, you can lay out your if/else if's in "entry" better:
Code:
    if (a == 1)
        price = 30;
    else if (a == 2)
        price = 60;
    else if (a == 3)
        price = 95;
    else if (a == 4)
        price = 90;
    else if (a == 5)
        price = 80;
    else if (a == 6)
        price = 45;
    else
        //// handle error
Or:
Code:
    switch (a) {
    case 1: price = 30; break;
    case 2: price = 60; break;
    case 3: price = 95; break;
    case 4: price = 90; break;
    case 5: price = 80; break;
    case 6: price = 45; break;
    default: //// handle error
    }
Or even:
Code:
    int values[] = {30, 60, 95, 90, 80, 45};
    if (a < 1 || a > 6)
        //// handle error
    else
        price = values[a-1];