Costco Web Member Savings Tracker

WHAT IT DOES

This tool helps you track savings on Costco purchases by extracting pricing data from product pages. It reads item names, regular prices, sale prices, savings amounts, savings percentages, and manufacturer rebate information directly from the page. The panel displays total savings for the current shopping trip, highlights items with active savings, and shows a detailed breakdown of each product's price and savings. Cumulative savings are tracked across browsing sessions, and the membership fee is subtracted to show net savings. A savings goal can be set to track progress toward earning back your membership cost.

WHERE IT RUNS

The script activates on Costco pages (costco.com), including product listings, shopping cart pages, and product detail views. It automatically detects product pricing data using multiple extraction strategies that work across different Costco layouts. The panel appears as a draggable overlay that stays accessible as you browse and add items to your cart.

HOW TO USE

Navigate to a Costco product listing or shopping cart page. The panel will appear showing the current trip's total savings, product list with regular and sale prices, and a savings breakdown. The summary shows total items, sale items, cumulative savings, and average savings per item. The membership section shows your fee, net savings after fee, and progress toward your savings goal. Set your membership fee using the "Fee" input and your savings goal using the "Goal" input. The "Scan" button manually updates the product data, "Reset Savings" clears cumulative savings history, and "Export" copies all savings data as JSON to your clipboard. The cumulative savings persist across browsing sessions, and each scan adds to the running total.

THE TECHNICAL MECHANISM

The script employs a multi-strategy DOM extraction approach for Costco's product interface. It first attempts structured selectors targeting known class names like .product-card, .item-card, and .product-tile, then falls back to heuristic detection of product containers based on content patterns including currency symbols and pricing indicators. Price extraction identifies multiple price points in the text—the highest value is treated as the regular price, and the lowest as the sale price. Savings are calculated as regularPrice - salePrice, and savings percentage is derived from this difference. Manufacturer rebate detection uses pattern matching for keywords like "rebate", "manufacturer rebate", or "manufacturer discount". Cumulative savings are stored using GM_setValue with a structured data object containing totalSavings, individual item records, and a history array with timestamps. The net savings calculation subtracts the user-defined membership fee from cumulative savings. The savings goal progress is calculated as a percentage of cumulative savings versus the goal. All settings are persisted using GM_setValue and reloaded on page load, maintaining the savings history across browsing sessions.

THE PANEL

The panel is fully draggable by its header and remembers its position on the page across sessions. It can be collapsed to a small bubble using the minimize button, then restored by clicking the bubble. The panel resizes automatically to fit its content and can be closed with the Escape key or by clicking the close button. The panel's position and state persist globally, so it returns to the same location on subsequent visits.

PLEASE NOTE

Requires the free BotGentz extension to run. Costco may update its site structure, which could affect the script's ability to detect pricing data — updates will be released as needed. All savings data is stored locally in your browser and is never transmitted externally. This tool is for informational purposes only and does not provide financial advice. The script does not modify your Costco account or perform any transactions. Savings calculations are based on the prices displayed on the page and may not reflect final checkout prices, taxes, or fees. Always verify final savings and costs with your Costco receipt.