I don't understand the attraction for all-inclusive. Surely, if you get a good package, then budgeting is not a problem?
At this time of year, all the best options will inevitably be booked up.
Avoid Little Palm Island. Frankly, I don't think it has ever been good, so if standards have declined, then I cannot imagine how bad it is now!
How about Four Seasons Costa Rica? Not all-inclusive, but packages certainly.