Money.cs

public class Money
{
    public readonly decimal Amount;
    public readonly string CurrencyCode;
        
    public Money(decimal amount)
        : this(amount, "en-us")
    { }

    public Money(decimal amount, string currencyCode)
    {
        Amount = amount;
        CurrencyCode = currencyCode;
    }

    public Money Convert(string currencyCode)
    {
        return new Money(Amount, currencyCode);
    }

    public override string ToString()
    {
        return Amount.ToString("C", CultureInfo.CreateSpecificCulture(CurrencyCode));
    }
}