.NET SortedDictionary vs OrderBy vs List.Sort

Program.cs

using System.Collections.Generic;
using System.Linq;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

namespace SortedDictPerf
{
    /// <summary>
    /// |      Method |     Mean |    Error |   StdDev |  Gen 0 | Gen 1 | Gen 2 | Allocated |
    /// |------------ |---------:|---------:|---------:|-------:|------:|------:|----------:|
    /// |        Dict | 361.7 ns |  7.07 ns |  7.26 ns | 0.1554 |     - |     - |     488 B |
    /// | DictOrderBy | 499.9 ns |  9.66 ns |  9.04 ns | 0.2651 |     - |     - |     832 B |
    /// |  SortedDict | 943.7 ns | 18.26 ns | 22.42 ns | 0.2241 |     - |     - |     704 B |
    /// </summary>
    [MemoryDiagnoser]
    public class Program
    {
        private static readonly List<(int Price, int Quantity)> Data = new()
        {
            (1, 2),
            (1, 3),
            (1, 4),
            (2, 4),
            (2, 2),
            (3, 5),
            (7, 5),
            (8, 5),
            (9, 5),
            (9, 15)
        };

        static void Main()
        {
            BenchmarkRunner.Run<Program>();
        }

        [Benchmark]
        public List<KeyValuePair<int, int>> Dict()
        {
            var result = new Dictionary<int, int>();
            foreach (var entry in Data)
            {
                if (result.TryGetValue(entry.Price, out var res))
                {
                    result[entry.Price] = res + entry.Quantity;
                }
                else
                {
                    result[entry.Price] = entry.Quantity;
                }
            }

            var list = result.ToList();
            list.Sort((x, y) => x.Key - y.Key);
            
            return list;
        }
        
        [Benchmark]
        public List<KeyValuePair<int, int>> DictOrderBy()
        {
            var result = new Dictionary<int, int>();
            foreach (var entry in Data)
            {
                if (result.TryGetValue(entry.Price, out var res))
                {
                    result[entry.Price] = res + entry.Quantity;
                }
                else
                {
                    result[entry.Price] = entry.Quantity;
                }
            }

            return result.OrderBy(x => x.Key).ToList();
        }

        [Benchmark]
        public List<KeyValuePair<int, int>> SortedDict()
        {
            var result = new SortedDictionary<int, int>();
            
            foreach (var entry in Data)
            {
                if (result.TryGetValue(entry.Price, out var res))
                {
                    result[entry.Price] = res + entry.Quantity;
                }
                else
                {
                    result[entry.Price] = entry.Quantity;
                }
            }

            return result.ToList();
        }
    }
}

SortedDictPerf.csproj

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net5.0</TargetFramework>
    </PropertyGroup>

    <ItemGroup>
      <PackageReference Include="BenchmarkDotNet" Version="0.13.0" />
    </ItemGroup>

</Project>