VRAMGlass

Pick an open-weight model and a quantization, see how much memory it needs, and find the GPUs that fit. Then check what those cards actually list for: used on eBay (US) and Xianyu (China), new on Amazon Japan, with price history, sample counts and freshness labels. Plus RAM prices, a GPU price index, plain-English guides, and an embeddable live price card with an MIT-licensed SDK. Free, no sign-up, 4 languages.