We have never paid more than $165 round trip for any of our flights. We are cruising in November and coming back the day after Thanksgiving (one of the MOST expensive travel days of the year) and still managed to get a good rate of $186.50. If you don't mind doing a little more yourself, you can really save yourself some money. Use the money you save to book another cruise onboard. 
I would Book separately. Through DCL they are correct you are guaranteed nothing. You will not have a direct flight (most likely). With DCL it would have cost me approximately 1,200
I went through American and got air far (direct flight early morning) for approximately 650.00. There are so many airlines out there. I would check for yourself before you book through DCL. They will give you what you want for 100.00 I think per person. You also do not have control on what airline you are taking. If you have small children and you have a connecting flight that is not for a couple of hours you could be sitting in an airport with them. I know this happened to some on this board. This is just my opinion. Good luck in what you decide.

