What a rip off! I was very surprised not to be offered the option of adding hold luggage at the time of booking,a couple of months ago, through Cheap O air .co.uk. I just went to manage my booking to add baggage and was horrified to see the charges have gone up hugely- it's £80 return for a 20kg bag and £30 return for a 15kg bag. So I just paid an extra £300 for 5 people to take a small bag! If i'd known at the time of booking I could have budgeted accordingly, or looked for a different flight. I used Easy Jet recently to book for another holiday, and they were fantastic- you added luggage and could even choose your seat at the time of booking.