Hello
Whether it makes sense to purchase an Annual Pass for one visit depends on the dates of your trip.
I booked the Caribbean Beach Resort for $144 per night for my dates in early July. Then when the AP rates came out this week, I was able to get the price reduced to $74 per night.
The Caribbean Beach Resort was recently refurbished, and I've heard great things about the size and decor of the rooms. I've always stayed in deluxe resorts before, but I am really excited about this trip to CBR. The landscaping looks lush and tropical. I've read so many good posts about this resort on this board
Also, only one person in your party needs an AP to qualify for the reduced rates at your resort. If you were each going to purchase a 5 (or more) Day Park Hopper Pass anyway, the Annual Pass is not that much more expensive and may make sense, if you can get the excellent discounts currently being offered.
If it were me, I would opt for MORE DAYS at a Disney moderate resort over fewer days at the deluxe. Days at Disney seem to fly bye! Seven days is probably the shortest length for a visit, if you want to see at least the highlights at each of the Disney theme parks (at less than a break-your-neck speed).
Whichever choice you decide will be magical. Best wishes for the best vacation yet!