Show HN: I made a price aggregator to find the best PC parts deals across eBay

(pcprice.watch)

15 points by tzoSkatzo a day ago | 10 comments

Started PC flipping as a hobby (buying used parts, building PCs, and selling them for a small profit). Found that focusing on used parts on eBay gives the best margins - like finding a GPU 20% below market, pairing it with other deals, and selling the complete build locally.

I discovered that eBay marketplaces (.com, .de, .co.uk etc.) often have different prices for the same items! Or just completely different items.

So I built an eBay price scanner for PC components. It scans listings across different Ebay markets, calculates median prices, and flags anything selling below market (including shipping costs to your location). It basically finds the best deal that is specific to your location.

It currently tracks GPUs, CPUs, RAM and motherboards across 6 eBay markets, updating every 8 hours.

Been using it myself for and it actually works!

Let me know, what you think. Would love to hear your feedback on making it more useful.

tzoSkatzo a day ago | next |

Technical detail for those interested:

Architecture: - Frontend: Vue.js with Tailwind CSS, hosted on Vercel - Backend: Python scripts running on Oracle Cloud VM - Data refresh: Every 8 hours via cronjob

The most interesting challenge was filtering legitimate PC part listings. eBay search isn't perfect - searching for "RTX 4090" returns lots of irrelevant items like brackets, broken cards, or water cooling kits.

I solved this using custom ML classifiers for each component type (GPU/CPU/RAM/Motherboard). Each classifier is trained on labeled eBay listings to identify legitimate parts.

This automated filtering is crucial since the scanner processes thousands of listings daily across different eBay markets and languages.

One other issue, is bypassing the eBay API limitations, since I query for thousands of items I need to somehow optimize it. So far, I'm caching useful information like Shipping, but eventually if I want to add more items and/or marketplaces, I will need to either implement a key rotation or ask ebay to extend their API limits.

Currently, I scan for around 10k eBay listings along with their shipping info.

atmanactive 21 hours ago | prev | next |

How do you confirm that the GPU you bought from eBay is really in 100% working order? CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok. RAM, you do memTestx86 and it's all clear. But MBDs on the other hand ... I had ~50% failure rate from eBay where a MBD would boot up and would look like it is working correctly, only to discover that there is something somewhere that's not working as expected months later. Hence, I'm curious about your approach to GPUs.

tzoSkatzo 14 hours ago | root | parent | next |

Thanks for your question.

That was a real concern of mine, for a long time. Business Wise: 1. eBay has a really good buyers protection. I've had items that were not delivered or dysfunctioning, and I got a full refund. No questions asked. 2. Make sure to check the sellers rating. - pcprice.watch also includes the sellers' rating.

But I understand that you are more asking about my approach for a GPU to work hardware-wise? Technical testing for GPUs: 1. I do PCB inspection, and I check the power connectors PCIe contracts. 2. I found out GPU-Z to be useful 3. And maybe the most telling gaming benchmark suite: 3DMark or gaming sessions

So far I haven't had any incidents that had made me lose money, and I do flip PC's quite often :)

atmanactive 10 hours ago | root | parent |

Ah, so you are willing to tinker with it. Sure, full inspection and testing cycle could reveal if the item is 100% ok. But, in that case I'm wondering if the price difference is worth it, considering the time spent. Then we could also call it "Refurbished", no?

zoky 16 hours ago | root | parent | prev |

> CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok.

Not necessarily. I had a Xeon once with a single bad core. It would boot fine and run for a while, but under heavy loads it would produce bad results, leading to a kernel panic due to a detected inconsistency. Disabling the defective core made the problem go away, so I eventually had the CPU replaced which fixed the issue.

I also had a Core i7 system recently that was experiencing inexplicable slowdowns while rendering video for a month or two. After replacing literally every other component in the system without resolving the problem, the CPU finally died and I was forced to replace it. The slowdowns went away immediately, so my conclusion was that the CPU was on the way out and that was causing the performance problems.

atmanactive 10 hours ago | root | parent |

Interesting. That never happened in my experience. Which generations were those defective ones? I mean, yes, overclocking and/or overheating the CPU could damage it, but I thought Intel had every possible self-defence protection enabled in the CPU.

atmanactive 9 hours ago | prev | next |

About the search: I just did my first search for the RTX 3050, but the very first result is GTX 1660. Given that this happens all the time on eBay, and, obviously on your site as well, I think there should be a cookie-based hide-this-one-forever UI affordance and functionality to alleviate this problem.

tzoSkatzo 9 hours ago | root | parent |

Yeah, it's funny the eBay API tends to return mostly irrelevant listings, and I have to classify them. Even then they are like 95% accurate, one thing I could potentially improve is use a classifier per model instead of per part type.

However, your feedback is noted, I'll try to add this asap.