It's like selling sand to a man who lives in the desert.....
Air conditioners will go on sale just as soon as you do not need one. When the heat of August breaks, retailers and wholesalers will be delighted to sell you this year's model for cheap. They don't want their warehouse filled with this years units because they take up space and depreciate.
Another reason why these folks do not want units hanging around for several seasons is the fear that the Federal Government will, with the stroke of a pen, make their inventory obsolete and leave them holding the bag.
If you think your AC unit might be giving up this summer see if you can nurse it along until September then do some shopping.