Honestly most of the standard extensions people recommend for vintage comps are pretty bloated and unreliable. I tested a bunch of them last month for old audio gear and had issues with massive data lag during peak hours. Avoid anything claiming to give you real-time arbitrage alerts unless you want your browser to freeze up mid-search.

• Terapeak is technically built-in now but the UI is clunky and misses a lot of localized price swings.
• ResaleResearch extension was okay for a week before it started throwing API timeout errors constantly.
• Keepa has the best backend data structure by far, though its interface takes some getting used to. Keepa actually handles historical pricing going back years without choking on Chrome memory limits. It costs a few bucks a month depending on the plan, but you cant rely on free tools when component prices are shifting this fast. Watch out for sketchy third-party extensions asking for full account permissions too. Just grab something with a stable data pipeline or youll waste half your sourcing trip waiting for pages to load.

Had a moment to think about this more after my initial browse. Are you mainly trying to track raw completed listings, or do you need something that automatically calculates fees and shipping into the profit margins too? Also, are you looking for an extension that stores this data locally or pulls everything fresh from the cloud each time?

Over the years Ive parsed thousands of historical data points for electronics reselling, and honestly relying purely on browser extensions for volatile vintage gear is a headache. Chrome extensions tend to choke on API rate limits when you need deep historical comps the most. Honestly just look up some recent YouTube tutorials about eBay data scrapers and extension workarounds, theres a really solid video that covers free Chrome tools and exact search strings for vintage electronics that pops up immediately if you search for it. Saves you a ton of trial and error before your weekend trip imo.