class Program
    {
        static void Main(string[] args)
        {
            var auctionInfo = JsonConvert.DeserializeObject<IEnumerable<AuctionInfo>>(File.ReadAllText(@"C:\datei.json"));
        }
    }

    public class AuctionInfo
    {
        public string BidState { get; set; }

        public uint BuyNowPrice { get; set; }

        public uint CurrentBid { get; set; }

        public int Expires { get; set; }

        public ItemData ItemData { get; set; }

        public uint StartingBid { get; set; }

        public string TradeState { get; set; }
    }

    public class ItemData
    {
        public long AssetId { get; set; }

        public byte RareFlag { get; set; }

        public byte Rating { get; set; }

        public long ResourceId { get; set; }

    }