🚀 Automate Your Sourcing: Why I Built an eBay Analysis Extension for Free

Fehrjung — Wed, 05 Aug 2026 09:56:43 +0000

Hey dev.to community!

If you are like me, you love messing around with tech, refurbishing old hardware, or flipping IT equipment as a side hustle. But let's be honest: manually calculating margins on eBay, checking price histories, and avoiding overpriced listings is an absolute time-sink.
To solve this, I built Fehr Algorithmus – a browser extension that injects a real-time data analysis dashboard directly into any eBay listing.
Here is why I built it, what it does under the hood, and why you should try it out if you do any tech sourcing.

🛠️ What the Extension Does

The extension acts as a smart layer on top of eBay, optimized specifically for IT and tech deals. Instead of scraping comparison sites manually, the tool gives you an instant layout of the vital signs of any listing:

Instant Median Pricing: It extracts the item's specifications and compares the current price against the market median (e.g., seeing a €540 MacBook next to a €265 median instantly flags a bad deal).
Automated Risk & Repair Assessment: It scans the listing details to classify the condition (e.g., "Kein Reparaturfall") and calculates an overall sourcing risk level (Low/Medium/High).
Status & Action Indicators: It tells you exactly what to do with flags like RESEARCH_ONLY, saving you from wasting capital on low-margin flips.
Affiliate & Partnerlink Checks: It detects if a listing provides clean affiliate validation or needs further user intent before generating links.

💡 Why You Should Install It

Stop Overpaying on Bad Deals: The UI immediately tells you if a price is mathematically implausible for resale.
Zero Tab-Switching: All the scraped data, seller stats (like 100% feedback), and item numbers are grouped into one compact, readable sidebar widget.
Optimized for Tech Assets: While generic price trackers look at everything, this algorithm is specifically tuned to handle complex IT specs (like distinguishing an i9 processor, 32GB RAM, and 1TB SSD configurations).

👉 Check it out: https://chromewebstore.google.com/detail/fehr-algorithmus-ebay-ana/jkhefpdlgmalpdpdlbaenckegagjhbda

I'd love to get your feedback on the UI/UX and features. What data points do you usually look for when sourcing tech online? Let me know in the comments!

Why I built a 400 KB native Linux tool to replace heavy AI for B2B Re-Commerce

Fehrjung — Wed, 24 Jun 2026 15:09:07 +0000

Refurbishers, ITAD teams, and B2B traders lose margin every single day — not because they lack AI, but because devices are misvalued, sorted too late, or processed with incomplete information. The problem is operational, not theoretical.

While the industry pours money into bloated, hallucinating AI stacks with unpredictable server costs, I chose the opposite path:
Radical lightweight engineering.

Fehr Algorithmus is a 400 KB deterministic logic core running natively on the Linux kernel.
No cloud. No GPU farms. No hallucinations.
Just millisecond‑fast, predictable logic built for real shop‑floor conditions — the same philosophy behind FehrWatch ERP.

⚡ What the system delivers in milliseconds
Instant Valuation
Enter a single device, paste an eBay link, or import a full XLSX list — the engine instantly returns the real market‑value median.
Device details, condition, and comps appear in one unified workflow.

Risk Automation
Automatic detection of red flags such as BIOS locks, expressed through a clear traffic‑light signal.

Repair Buffers
Spare‑part deductions and repair buffers are integrated directly into the margin math — the same arbitrage logic that secured an MSI Delta 15 for €463 against a €900 market value.

Batch Throughput
Import, deduplicate, classify, value, and document large hardware lists — without switching tools or juggling ten browser tabs.

🛠 Built for the shop floor, not the boardroom
This system wasn’t designed in a meeting room.
It comes from decades of hands‑on problem‑solving, where speed, determinism, and reliability matter more than buzzwords.
www.fehrwatch.de

DEV Community: Fehrjung

🚀 Automate Your Sourcing: Why I Built an eBay Analysis Extension for Free

Why I built a 400 KB native Linux tool to replace heavy AI for B2B Re-Commerce