If you booked a *GT rate, those tend to be last minute with a lot of restrictions. They frequently are as good or perhaps even better than opening day depending.
It honestly comes down to preference... we jumped ship so to speak to
RCCL in 2017 for a southern itinerary and honestly just didn't enjoy sailing with them (at least on that size of ship). It was then worth it to us to pay a little more to stick with
DCL for two more of their southerns (on the Wonder). The current price points I'm seeing for Europe make me uncomfortable as well... 9K or so just for two for a week is a lot to ask. If we had a family of 4 or 5 maybe it wouldn't seem so high since /everything/ is more expensive when you're talking about 4 or 5 people? I've heard that seeing Greece from a ship is a great way to go, given all the islands, but for Italy a land trip may be preferable if you are comfortable taking care of yourselves from city to city. Our one and only Europe cruise on DCL was to see the Norwegian Fjords, and in the end we really wished we'd done a land tour. The hours between 6 & when we docked again the next night was a cruise we could have done literally anywhere and we honestly wished to stay ashore and eat in local restaurants, drive a little further than we had time for, etc. I *may* do Greece at some point but I'm not sure if it would be on DCL or not at these prices. These are very common routes... decisions decisions!
Obligatory "we are very comfortable and make far more than we need", but in no way do we make enough money that it is no object.