Parse the UE4 Vault API to catalogue it in a spreadsheet (exports the JSON -> CSV)

Program.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace UnrealVaultParser
{
    class Program
    {
        private class VaultItem
        {
            public string ItemId { get; set; }
            public string Title { get; set; }
            public string Description { get; set; }
            public string SellerName { get; set; }
            public IList<string> Owners { get; set; } = new List<string>();
        }

        static void Main(string[] args)
        {
            var items = new Dictionary<string, VaultItem>();

            // JSON files in here, named "owner_page1.json" "owner_page2.json"... etc
            foreach (var file in Directory.EnumerateFiles(@"C:\Users\alan\Desktop\New folder"))
            {
                var owner = Path.GetFileNameWithoutExtension(file).Split("_")[0];

                var obj = JObject.Parse(File.ReadAllText(file));


                foreach (var item in obj["data"]["elements"])
                {
                    var itemId = item.Value<string>("catalogItemId");
                    var itemTitle = item.Value<string>("title");
                    var itemDescription = item.Value<string>("description");
                    var itemSellerName = item["seller"].Value<string>("name");

                    if (items.ContainsKey(itemId))
                    {
                        items[itemId].Owners.Add(owner);
                    }
                    else
                    {
                        items.Add(itemId, new VaultItem
                        {
                            ItemId = itemId,
                            Title = itemTitle,
                            Description = itemDescription,
                            SellerName = itemSellerName,
                            Owners = new List<string> { owner }
                        });
                    }
                }
            }

            using (var output = File.OpenWrite(@"C:\Users\alan\Desktop\New folder\output.csv"))
            using (var sw = new StreamWriter(output))
            {
                sw.WriteLine("Title,Description,Seller,Link,Owners");

                foreach (var item in items)
                {
                    sw.WriteLine($"\"{Escape(item.Value.Title)}\"," +
                        $"\"{Escape(item.Value.Description)}\"," +
                        $"\"{Escape(item.Value.SellerName)}\"," +
                        $"https://www.unrealengine.com/marketplace/en-US/item/{item.Value.ItemId}," +
                        $"\"{string.Join(",", item.Value.Owners.OrderBy(x => x))}\"");
                }
            }
        }

        private static string Escape(string str) => str.Replace("\"", "\"\"");
    }
}