using System;

using Newtonsoft.Json;  

using System.Globalization;

​

public class Program

{

    public static void Main()

    {

        var t = new Demo();

        t.Start();

    }

}

​

public class Demo {

    public void Start(){

        var json = "{\"productoUid\":\"p1\",\"catalogUid\":\"c9b38bcbecee4b27b65fbe9b81020009\",\"categoryUid\":null,\"photos\":[],\"referencia\":\"r1\",\"nombre\":\"UNO\",\"descripcion\":\"UNO\",\"keywords\":\"kp1\",\"precio\":1.0000,\"cantidad\":10.0000}";

        Result m = JsonConvert.DeserializeObject<Result>(json); 

        string.Format("Cantidad: {0} Precio: {1}", string.Format("{0:0}", m.cantidad),  m.precio.ToString("C", new CultureInfo("es-CO"))).Dump();

    }

}

public class Result {

    public decimal precio {get;set;}

    public decimal cantidad {get;set;}

}