Spice Jungle, in addition to a fabulous line of herbs and spices, sells an ounce of vinegar powder for less than $6, with free shipping (and a 5% discount for sign-up). Apple cider, white balsamic, white distilled, red wine, and malt flavors are available.
Powdered vinegar is the latest ingredient to get rave reviews, and you can make make a DIY version of your own flavored vinegars by boiling the vinegar with baking soda until the liquid evaporates. You can also dehydrate the lees from the bottom of a bottle (not the mother, though). Still another way to DIY is to soak stale bread in vinegar, let it dry out in a very low-temperature oven, and grind it up in the food processor.
One reason you might want to go to the effort of making your own powdered vinegar is that commercial powdered vinegars contain anti-clumping agents like maltodextrin (sugar).
Suggestions for use: sprinkle on air-fried “french fries,” stir-fried vegetables, oily fish like macherel or salmon