Log prices for products I'm watching every day

Every morning, check the current price and stock status for each product in my watchlist [sheet link or paste product URLs]. Open each product page, read the live price (use the buy-box price, not crossed-out list prices), and append today's row to the price log: date, product, price, currency, in stock or not, and the link. If a price dropped versus the last logged price, call it out clearly at the top of your run summary with old price, new price, and percent change — same if something comes back in stock. If a page errors or the product is gone, log UNAVAILABLE rather than skipping silently. Keep the log append-only so I can see history over time.