PlayerShop

using System;
using System.Collections.Generic;
using System.Linq;

namespace PlayerShop
{
    class Program
    {
        static void Main(string[] args)
        {
            List<Item> itemsForSale = new List<Item> { new Item(150, "Axe"), new Item(250, "Sword"), new Item(60, "Healing potion"), new Item(40, "Mana potion") };
            Seller seller = new Seller("Prodavan", 100, itemsForSale);
            List<Item> playerItems = new List<Item>();
            Player player = new Player("Vasiliy", 600, playerItems);
            while (true)
            {
                Console.Clear();
                Console.WriteLine("Gold: " + player.Gold);
                Console.WriteLine("Seller's Gold :" + seller.Gold);
                Console.WriteLine("1 - seller items\n2 -player items\n3 - buy item ");
                int userInput = Convert.ToInt32(Console.ReadLine());
                switch (userInput)
                {
                    case 1:
                        seller.ShowItems(itemsForSale);
                        break;
                    case 2:
                        player.ShowItems(playerItems);
                        break;
                    case 3:
                        seller.ShowItems(itemsForSale);
                        Console.WriteLine("Введите номер предмета, который вы хотите купить:");
                        int userChoice = Convert.ToInt32(Console.ReadLine());
                        if (itemsForSale[userChoice - 1].Price <= player.Gold)
                        {
                            player.BuyItem(seller, userChoice - 1, itemsForSale, playerItems);
                        }
                        else
                        {
                            Console.WriteLine("Not enough gold");
                        }
                        break;
                }
                Console.WriteLine("Нажмите любую клавишу...");
                Console.ReadKey();
            }
        }

        class Seller
        {
            public int Gold { get; private set; }
            public string Name { get; private set; }

            public List<Item> ItemList = new List<Item>();
            public Seller(string name, int gold, List<Item> items)
            {
                Gold = gold;
                Name = name;
                ItemList = items;
            }

            public void ShowItems(List<Item> forSale)
            {
                foreach (var item in forSale)
                {
                    Console.WriteLine($"{item.Name} - {item.Price}");
                }
            }

            public void SellItem(int itemIndex)
            {
                Gold += ItemList[itemIndex].Price;
            }
        }

        class Player
        {
            public int Gold { get; private set; }
            public string Name { get; private set; }

            List<Item> ItemList = new List<Item>();

            public Player(string name, int gold, List<Item> items)
            {
                Name = name;
                Gold = gold;
                ItemList = items;
            }

            public void BuyItem(Seller seller, int itemIndex, List<Item> sellerItems, List<Item> playerItems)
            {
                var tempItem = sellerItems[itemIndex];
                Gold -= sellerItems[itemIndex].Price;
                seller.SellItem(itemIndex);
                sellerItems.RemoveAt(itemIndex);
                playerItems.Add(tempItem);
                Console.WriteLine("Вы купили предмет - " + tempItem.Name);
            }
            public void ShowItems(List<Item> playerItems)
            {
                foreach (var item in playerItems)
                    Console.WriteLine(item.Name);
            }
        }

        class Item
        {
            public string Name { get; private set; }
            public int Price { get; private set; }

            public Item(int price, string name)
            {
                Name = name;
                Price = price;
            }
        }
    }
}