Use this script to do high value conversions for your games.

MonetaryManager.cs

namespace Manager
{
    public static class MonetaryManager
    {
        private static readonly char[] SplitChar = new char[2] { ',', '.' };

        public static string ConvertCurrency(double currency)
        {
            return currency switch
            {
                >= 1e+45D => RemoveZero((currency / 1d + 45D).ToString("N1")) + "kk",
                >= 1e+42D => RemoveZero((currency / 1d + 42D).ToString("N1")) + "jj",
                >= 1e+39D => RemoveZero((currency / 1d + 39D).ToString("N1")) + "ii",
                >= 1e+36D => RemoveZero((currency / 1d + 36D).ToString("N1")) + "hh",
                >= 1e+33D => RemoveZero((currency / 1d + 33D).ToString("N1")) + "gg",
                >= 1e+30D => RemoveZero((currency / 1d + 30D).ToString("N1")) + "ff",
                >= 1e+27D => RemoveZero((currency / 1d + 27D).ToString("N1")) + "ee",
                >= 1e+24D => RemoveZero((currency / 1d + 24D).ToString("N1")) + "dd",
                >= 1e+21D => RemoveZero((currency / 1d + 21D).ToString("N1")) + "cc",
                >= 1e+18D => RemoveZero((currency / 1d + 18D).ToString("N1")) + "bb",
                >= 1e+15D => RemoveZero((currency / 1d + 15D).ToString("N1")) + "aa",
                >= 1e+12D => RemoveZero((currency / 1d + 12D).ToString("N1")) + "T",
                >= 1e+9D => RemoveZero((currency / 1d + 9D).ToString("N1")) + "B",
                >= 1e+6D => RemoveZero((currency / 1d + 6D).ToString("N1")) + "M",
                >= 1e+3D => RemoveZero((currency / 1d + 3D).ToString("N1")) + "K",
                _ => currency.ToString("N0")
            };
        }

        private static string RemoveZero(string value)
        {
            var result = value.Split(SplitChar);
            return result.Length > 1 && result[1][0] != '0' ? $"{result[0]}.{result[1][0]}" : result[0];
        }
    }
}