Today, you can choose from leather, plastic, synthetic fabrics, or any of these in combination. Prices display a similarly wide range. Spend as much money as you can to get a good-quality boot that fits comfortably but snugly when you're wearing ski socks.
Plastic boots can offer several advantages over leather.
They are sometimes less expensive, and are generally warmer and more waterproof. Some boots have a locking, hinged cuff that allows the boot to serve a wider range of functions. You can leave the cuff unlocked for diagonal stride or hill climbing, or fasten it for rigidity on descents. The best approach to boot shopping is to seek the counsel of ski instructors or ask for advice at well-run ski shops. As a general rule, the wider the ski you choose, the more torque it takes to control it, and thus the bigger and stiffer the required boot to deliver the necessary leverage.