we never travel in high season. always spring, fall, or even summer sometimes
We usually travel to Cayman in the lower seasons also because it is cheaper and less crowded and to celebrate our anniversary. Spring is still considered the high season due to Spring Break and Easter Vacation, and this year Easter is late (April 21) so you may not see prices start to drop until May.
You haven't mentioned how much diving you want to do on vacation? Or the other things that you like to do on vacation, and that makes a difference to the costs and the best location.
Cayman has always been a higher priced option as compared to some other Caribbean destinations, and it has gotten more expensive in recent years for several reasons. The US dollar has always been disadvantaged next to the Cayman dollar and the Canadian dollar has really suffered in comparison.
Cayman is a first-world country with good roads, fine health care facilities, high standards for rental accommodations and diving operations, good mosquito-abatement programs, excellent restaurants and there are no concerns about eating the food or drinking the water, and that all costs money. People feel safe exploring Cayman on their own and that is not true of some other Caribbean destinations. And of course the diving is very good and near the shore without long boat rides, and the Seven Mile Beach is a big attraction for many people.
Some of the more recent factors that have contributed to a surge in Cayman's tourist popularity include the terrible hurricane season of 2017 that damaged many other popular Caribbean destinations that may still be rebuilding, and the fact that Cayman is one of the few tropical destinations that is not on the CDC's Zika warning list - and so adults of child-bearing age feel safer traveling there.
Those factors have made the island an even more attractive destination recently and so there have been breaking numbers recorded for stay-over tourists and cruise ship visitors and that has driven up the prices.
That all makes sense but none of that helps you and I totally understand. When we started out diving the price was the biggest concern and we did several trips driving all the way from the Midwestern US to southern Florida and staying in very modest accommodations, just to have the chance to dive in warm water with tropical sea creatures.
One of our earliest trips was to Jamaica and we stayed in an inexpensive place and lugged our dive gear on jitney buses to get to the dive boats! We did an early trip arranged by our local dive shop to Grand Cayman and we liked the diving but didn't like the prices. It took us a long time to come back to Cayman but now that we are older and money is a little easier, but still an important factor, we have to come to really appreciate some of the advantages that Cayman offers.
There are a couple of big ticket items that Cayman offers that may be cheaper than other Caribbean destinations. It is usually pretty easy to get there, there are lots of direct or one-stop flights from the US and Canada and you can often find good prices for flights. Also there are a lot of rental car agencies on GC and that helps to keep the prices down so rental cars are usually pretty reasonable. So you have to weigh all the factors when considering a vacation destination.
We can stay and dive much more cheaply in Roatan than Cayman for example, but it can be difficult and expensive to get there - and I wouldn't want to rent a car because the roads are bad and some areas may not be safe to explore. Plus, you have to be careful about eating the food and drinking the water and also take precautions against mosquito-borne diseases; and that all adds to the expense and decreases the attractiveness of a vacation destination IMO.
I hope that you are able to find an option that will work for you on GC, but it might be better to travel someplace else this year and wait until the Canadian dollar is stronger before returning to Cayman; good luck finding a great vacation wherever you decide to go!