Hold on tight to the graphics cards you have, because those sitting on retailer shelves are about to get a lot more expensive, irrespective of whether you prefer AMD or Nvidia. Last week, Nvidia GPUs were confirmed to be getting a substantial price hike, with anything between 20% and 30% being reported. That gave AMD the perfect moment to communicate a price increase of its own, with market analyst Harukaze571 reporting that the company had been waiting for Nvidia to…