Special summation of integer array elements

I looked at this question and thought that I could find a much simpler way of doing this, here is the criteria that was given:

My current task is to find a score from an array where the highest/lowest scores have been taken away, and if the highest/lowest occur more than once (ONLY if they occur more than once), one of them can be added:

E.g. int[] scores = [4, 8, 6, 4, 8, 5]

therefore the final addition will be \$\sum{4,8,6, 5} = 23 \$.

Another condition of the task is that LINQ cannot be used, as well as any of the System.Array methods

Here is what I came up with: (Link to Answer)

static void Main(string[] args)
{
    // take an array and sum the distinct numbers
    int[] numberArray = { 4, 8, 6, 4, 8, 5 };
    int[] numberArray2 = { 4, 4, 5, 6, 8, 8 };

    Console.WriteLine(sumSpecial(numberArray).ToString());
    Console.WriteLine(sumSpecial(numberArray).ToString());

    Console.ReadLine();
}

static int getHighestScore(int[] integerArray)
{
    var high = 0;
    foreach (int number in integerArray)
    {
        high = high < number ? number : high;
    }
    return high;
}

static int getLowestScore(int[] integerArray)
{
    var low = int.MaxValue;
    foreach (int number in integerArray)
    {
        low = low > number ? number : low;
    }
    return low;
}

static int sumWithoutHighAndLowScores(int[] integerarray)
{
    int sum = 0;
    int high = getHighestScore(integerarray);
    int low = getLowestScore(integerarray);
    foreach (int number in integerarray)
    {
        if (number != high && number != low)
        {
            sum += number;
        }
    }
    return sum;
}

//sum of numbers using high or low only if there is a duplicate of high or low
static int sumSpecial(int[] integerArray)
{
    var sum = sumWithoutHighAndLowScores(integerArray);
    var high = getHighestScore(integerArray);
    var low = getLowestScore(integerArray);

    var highs = 0;
    var lows = 0;
    foreach (int number in integerArray)
    {
        if (number == high) { highs++; }
        if (number == low) { lows++; }
    }
    if (lows > 1) { sum += low; }
    if (highs > 1) { sum += high; }

    return sum;
}

What could be done better or more efficiently without losing the intentions of the exercise?