using System;

using System.Data;

using System.Globalization;                 

using System.Linq;

using System.Collections;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {   

        ParseCurrencyWithSymbol("$2.10").Dump();

        ParseCurrencyWithSymbol("£2.10").Dump();

        ParseCurrencyWithSymbol("€2,10").Dump();

        //decimal.Parse("$2.10", NumberStyles.Currency | NumberStyles.AllowDecimalPoint).Dump();

        //decimal.Parse("£2.10", NumberStyles.Currency | NumberStyles.AllowDecimalPoint, CultureInfo.CreateSpecificCulture("en-GB")).Dump();

        //decimal.Parse("€2.10", NumberStyles.Currency | NumberStyles.AllowDecimalPoint).Dump();

    }

    public static decimal ParseCurrencyWithSymbol(string input)

    {

        var cultures = CultureInfo.GetCultures(CultureTypes.AllCultures)

            .GroupBy(c=> c.NumberFormat.CurrencySymbol)

            .ToDictionary(c=> c.Key, c=>c.First());

        var culture = cultures.FirstOrDefault(c=>input.Contains(c.Key));

        decimal result = 0;

        if(!culture.Equals(default(KeyValuePair<string,CultureInfo>)))

        {

            result = decimal.Parse(input, NumberStyles.Currency | NumberStyles.AllowDecimalPoint, culture.Value);

        }

        else

        {

            if( !decimal.TryParse(input, out result))

            {

                throw new Exception("Invalid number format");

            }

        }

        return result;

    }

}

​

​