An old script I found in my notes, archival purposes

robloxItem.js

// Note: This works because these items have multiple products linked to them, and one of those products is still for sale.
// Contact: twitter.com/h0nde
// Date: 2019-03-22
// Open a window at roblox.com -> press F12 -> click the console tab button -> paste script -> press enter

var productIds = [
  "51119013", // Slime Cape
  "51119443", // Slime Sunglasses
  "45038518", // Festive Winter Shades
  "54591332", // Yondu’s Fin
  "37990657", // Dog Man Virtual Book
];

productIds.forEach(function (productId) {
  $.ajax("https://economy.roblox.com/v1/purchases/products/" + productId, {
    method: "POST",
    headers: { "X-CSRF-TOKEN": Roblox.XsrfToken.getToken() },
    dataType: "json",
    data: {
      expectedCurrency: 0,
      expectedPrice: 0,
      expectedSellerId: 1,
    },
    success: function (data) {
      if (data.purchased) {
        console.log("Bought", data.assetName);
      }
    },
  });
});