The governments in the US and Canada will still send you tests FREE. It is the testing process that may or may not be free. Proctoring costs as little as $14.99. Cheap.
My county health dept offers free PCR tests for those with symptoms, but these don't work for travel as 2-3 day results.
You might get it done for free, but spending a few dollars is insignificant compared to the cost of a cruise.