You need a rechargeable wireless presenter clicker that won't die halfway through a slide deck and will last you for years, meaning you buy it once instead of replacing a cheap one every six months. Look for models with solid build quality, a bright green laser, and USB-C charging so you aren't constantly hunting for AAA batteries.
Wait for standard office supply promotional weeks to shop, and keep an eye on the release cycle. When the brand drops a new version with minor tweaks, last year's model usually goes on sale while keeping almost all the same actual features.
The 0% intro window is a deadline, not free money, so make sure you clear the balance before those 18 months are up. If you leave any of that $450 on the card when the period ends, standard interest kicks in on the remaining amount.