If you don't want to shell out that kind of cash on a nearly 20-year-old pack of sauce, you can always try to make the Szechuan sauce at home. YouTube channel Binging with Babish has got you covered there with the above video.
The video showcases three different recipes that are all relatively simple: a traditional, spicy Szechuan sauce recipe, a version that the YouTube channel found on Reddit, and a mishmash of some of McDonald's other sauces.
Pick whichever one is to your personal liking, and go ahead and take a crack at it at home. Or, you can do what Binging with Babish did and just mash all three up together at the end.
While I've never had the privilege to taste the original Szechuan sauce, I'm sure that these recipes are all relatively close.
At the very least, these recipes will hold us over until McDonald's brings back the Szechuan sauce, which they may do for the live-action Mulan movie coming out next year.
And if McDonald's doesn't bring the sauce back, at least we'll have these replicas to make our own.