I used Costco once a few cruises ago and I won't ever again. We booked about two months out from sailing & shame on me for not being more diligent. Costco cruise has nothing to do with actual Costco itself. It's an independent TA. Their customer service isn't on par whatsoever.

BJ's actually had a better price ultimately. Costco wouldn't match. I was supposed to have a "free upgrade". Costco said that none of those cabins were available to them. My price went down on the line's site directly. Costco wouldn't lower AND unlike being able to upgrade for free (as opposed to a price adj.) as when booking directly through the line, Costco wouldn't upgrade either. Of course I was stuck in dealing with Costco & the line wouldn't talk to me since I had a TA. I learned the hard way and will think twice before going through them again. I ended up cancelling my membership after dealing with them on this fiasco.