Print-on-Demand Margin Calculator Overlay

WHAT IT DOES This userscript helps print-on-demand sellers calculate and optimize their profit margins directly on product pages. It scans pages on Redbubble, Printful, Teepublic, Society6, Zazzle, and similar sites to extract product base prices, retail prices, and production costs. It then calculates and displays key metrics—profit per item sold, profit margin percentage, and markup percentage. The script includes an interactive calculator that lets you adjust the selling price in real time to see the impact on margin and profit. You can set a target margin percentage and the script will suggest the optimal retail price to achieve it. It also identifies the product type (t-shirt, mug, poster, hoodie, etc.) and highlights products with the highest profit potential. WHERE IT RUNS The script works on print-on-demand product pages—Redbubble, Printful, Teepublic, Society6, Zazzle, and similar custom merchandise sites. It runs entirely within your browser, reading only the visible content of the current page. It does not track your browsing history, access other tabs, or send any data externally. All calculations are performed locally. HOW TO USE After installation, open the panel by clicking the tool's icon in the BotGentz sidebar. The script auto-scans product pages on load (toggle this on/off). It displays a calculator panel showing the retail price, production cost, profit, margin %, markup %, and a performance rating. Use the "Try different price" input to experiment with retail prices—enter a new price and click "Calculate" to see updated margin and profit. Use the "Target margin" section to set a desired profit margin percentage and click "Suggest price" to get the recommended retail price. The panel updates instantly with new metrics. Use "Clear calculator" to remove the display. THE TECHNICAL MECHANISM This script uses DOM traversal and price extraction to find product pricing data. It scans for retail price using common selectors like .price, .product-price, .selling-price, and [class*="price"]. For production costs, it looks for .base-price, .production-cost, .cost, and [class*="base"]. If no explicit cost is found, it uses a product-type estimate (T-Shirt: $8, Hoodie: $18, Mug: $5, Poster: $4, Phone Case: $7, Bag: $10) based on product name detection. The script calculates profit as retail price minus production cost, margin as (profit / retail) × 100, and markup as (profit / cost) × 100. The interactive calculator uses these formulas in real-time with user-adjusted retail prices. The price suggestion feature solves for retail price given a target margin: suggestedPrice = productionCost / (1 - targetMargin/100). The script also provides color-coded performance ratings—green for excellent margin (≥50%), yellow for good (30-49%), orange for low (15-29%), and red for very low (