Every price-tracker-as-a-service wants an account, has alert limits, and eventually asks for a subscription - to tell you that a number on a webpage went down. If you can run Python on your own machine, you do not need any of it.

Here is the whole system: a script on a cron schedule that fetches the page, pulls the price out, appends a row to a CSV, and pings you on Telegram or email only when the price crosses your target.

How it finds the price (3-tier)

  1. Your CSS selector - if you give it one, it wins. Best for sites with weird markup.
  2. og:price:amount meta tag - most modern storefronts (Shopify, WooCommerce, most e-commerce templates) expose this.
  3. JSON-LD structured data - the "price": field in the page's schema.org block.

The fallback chain covers most shops you will ever watch. For stubborn ones, right-click the price, Inspect, copy a selector, done.

The config is one JSON file 

{ "products": [ {"name": "gpu", "url": "https://shop.example/gpu", "target": 599.00}, {"name": "coffee", "url": "https://shop.example/beans", "drop_pct": 15} ] }

Alert when the price hits a target, or when it drops by a percentage. One fetch per product per run - polite by design.

The schedule is one line 

0 9,21 * * * cd /path/to/kit && python3 monitor.py

Two checks a day, 7 AM and 9 PM. Change it to hourly if you are hunting a flash sale. On Windows, the README includes the Task Scheduler equivalent.

Two honest limitations

  • Sites occasionally redesign their HTML. When that happens, updating the selector field in your config is the entire maintenance cost.
  • This is not a distributed crawling service. It is for watching a handful of products from your own machine - keep it low-volume and follow each site's terms.

Who this is for

Anyone waiting on a GPU price drop, tracking supplier listings, or holding a holiday shopping list who does not want yet another web app and account - just a script on their own machine, with the price history in their own CSV.

The whole thing is small on purpose: one readable script (about 200 lines), the JSON config, a README with selector-finding tips and ready-made cron/Task Scheduler lines, Telegram bot setup in five minutes, and an offline fixture so you can try it without touching any website. You can build it yourself in an evening from the description above.

If you would rather skip the build, I packaged exactly that as the Price Monitor Kit - a $1 instant download, priced at $1 on purpose while I collect the first round of honest reviews. If it disappoints, the product Q&A is right there; that is what the price is for.

Either way: stop checking prices by hand. Let cron do the staring at webpages - it is better at boredom than you are.