Very rough userscript to expose exact inventory data on Canadian games retailers BGB and 401G

OLGS_CA_game_inventory_hack.user.js

// ==UserScript==
// @match https://store.401games.ca/*
// @match https://www.boardgamebliss.com/*
// ==/UserScript==

const is401 = document.location.host.indexOf("401") > -1;
function getProduct() {
    try {
        if (is401) {
            const wrapper = document.getElementById("ProductJson-product-template");
            if (wrapper)
            {
                return JSON.parse(wrapper.textContent);
            }
        } else {
            const decl = document.getElementById("content");
            if (decl)
            {
                const scr = decl.firstElementChild;
                if (scr instanceof HTMLScriptElement)
                {
                    eval(scr.textContent);
                    return SPOParams.product;
                }
            }
        }
    } catch (e) {
        console.error("Hit error while trying to find product info: ", e);
    }
}

function getTarget () {
    if (is401) {
        return document.getElementById("variant-inventory");
    } else {
        const q = document.getElementById("quantity");
        if (q) {
            return q.parentElement.children[0];
        }
    }
}

const product = getProduct();
if (product && product.variants) {
    if (product.variants.length === 1) {
        const site = getTarget();
        if (site) {
            site.style.color = "blue";
            site.innerHTML = "Inventory: " + product.variants[0].inventory_quantity;
        } else {
            console.error("No inventory label found");
        }
    } else {
        console.error("Product had " + product.variants.length + " variants. Unable to consolidate.");
    }
} else {
    console.error("No product data JSON found");
}