How this index works
Once a month we record the typical used price of the local-AI hardware everyone actually shops for — the cards and Macs from our tracked database whose best deals live on the secondhand market. Each check appends to a public history (raw data here), so the trends, ranges, and sparklines get more useful every month. Readings are currently hand-verified against live marketplace listings; we're moving to automated daily medians from eBay's official API, and the method column in the data will say which is which.
Honest caveats
These are asking-price figures, not final sold prices — sold typically lands 10–15% below asking, but the trend direction is the same. "Typical" means we ignore outliers: the suspiciously cheap for-parts listing and the delusional $2,000 3090 both get skipped. Use the index for timing ("are 3090s drifting up or down?"), the cost calculator for whether to buy at all, and Can I run it? for what the hardware actually runs. Listing links are eBay affiliate links (disclosure) — they never affect the recorded prices.