Since their release, graphics cards became expensive. Stemming from the crypto boom and miners buying up stock to use them. As well as the pandemic shutting down factories has meant a shortage of products. As well as transport problems meant scalpers were also taking advantage and prices inflated with everyone trying to buy them up.
Now that the crypto market has crashed, it has become unprofitable to keep mining with energy prices rising too. So the demand has fallen and the miners have sold off their wares. And with manufacturing continuing at the same rate the stock has increased. While demand has gone down it has meant prices have been returning to normal.
And now that the new series of graphics cards are expected from AMD and Nvidia they will want to get rid of their stock. As they will want to have stock of the new cards instead. Therefore we see heavy discounts on current cards, and delays to the next series.