Improve design pattern for Service offer case study

I have designed classes for the system as below diagram shown:

public abstract class Service
{
    public abstract double price { get; }
    public int quantity { get; set; }
    public double Cost { get { return price * quantity; } }
}


public class FaxService : Service
{
    public FaxService()
    {

    }

    public override double price
    {
        get { return 1; }
    }
}

public class PrintingService : Service
{
    public PrintingService()
    {

    }

    public override double price
    {
        get { return 0.5; }
    }
}

public class ColorPrintingService : PrintingService
{
    public ColorPrintingService()
    {

    }
}

I have few different services inherit from Service class which are Fax, Scan and Printing. The ColorPrinting from PrintingService because I would like to reuse back the PrintingService price, for example

this.price = this.price + 10;

as ColorPrinting price. If any price update in PrintingService, it will reflect to ColorPrinting too.