Trading Card Marketplace Price Guide Overlay

WHAT IT DOES

Trading Card Marketplace Price Guide Overlay scans the current page for trading card listings, extracting card names, sets, grades, prices, and seller information from marketplace pages (eBay, TCGplayer, COMC, etc.). The floating panel shows price guide comparisons across listings with market price estimates, price range indicators, and value assessments. Quick-reference price tiers (high, average, low) with color-coded indicators help identify deals. Add custom price notes and track personal collection value. Export price guide data as CSV or text for collection management. Cards priced above or below market averages are highlighted, and price trends across listings are tracked.

WHERE IT RUNS

Works on any trading card marketplace page, including eBay, TCGplayer, COMC, Beckett Marketplace, and other card selling platforms. The script detects card listings using common selectors and can also fall back to general item cards. It works best on pages with structured listings containing card names, prices, and seller information.

HOW TO USE

The panel displays all detected cards with their prices, grades, sets, and sellers. Click "Scan Listings" to detect cards from the current page. Market statistics show average, median, and price range across all detected cards. Each card is color-coded by price tier: green for above average (high), yellow for at market, and red for below average (low). Add price notes to any card for collection tracking. Export the data as text for research or collection management. The panel shows grade indicators and set names to help identify specific cards.

MECHANISM — CARD EXTRACTION WITH MARKET STATISTICS CALCULATION

The script extracts trading card listings using a multi-strategy approach. It first attempts to find listing containers using common marketplace selectors (.listing, .item, .product). From each container, it extracts title, price, grade, seller, and set information using targeted sub-selectors. The price parser handles various currency formats and extracts numeric values. Market statistics are calculated from all detected prices, including average, median, min, and max. Each card's price tier is determined by comparing it to the market average: high (20% above average), average (within 20%), or low (20% below average). The set name is detected either from a set-specific element or by matching common set names in the card title.

THE PANEL

The floating panel is fully draggable and remembers its position per domain. Click the minimize button to collapse it to a small bubble, or press Escape to hide it. The panel automatically adjusts to different screen sizes and can be resized to show more content. All settings and price notes are saved per domain. The panel integrates smoothly with any page layout using the BGPanel framework, maintaining clean separation from page content.

PLEASE NOTE

This script requires the free BotGentz extension to run. It does not send any data to external servers; all extracted card data, price notes, and settings remain entirely local to your browser using GM_setValue. The script never reads password fields, hidden inputs, or file inputs. It stores only card names, prices, grades, sets, seller information, and user-entered notes from publicly visible page content. Listing detection depends on the page structure; if cards are not detected, use the "Scan Listings" button to refresh extraction. Market statistics are calculated from the current page's listings only and should be used as a reference. Data persists across browser sessions and is isolated per browser profile.