Costco Gold Tracker

For checking a price tag in store — no refresh needed. Spot pre-fills from the last price you fetched (via "Refresh prices" below, or your last visit); edit it if it's stale. Weight defaults to 1 oz for the bar this tracker follows — change it for a different size.

Card rates below are general/no-bonus-category cash-equivalent rates (Costco.com purchases don't trigger travel/dining/gas bonuses on most cards). These are best-known figures, not live-verified this session — check your card's current terms. Pick "Custom" to type your own. CollectPure fee defaults to their published 0.75% Bullion Fee Rate — edit if selling a different metal/product type (Silver/Platinum/Palladium is 1.00%, Numismatic is 1.5%).

"Refresh prices" fetches CollectPure's live bid + spot gold price, and Costco's price via costcogoldinventory.com's public inventory report — both through a proxy (needed to work around CORS; see refresh_server.py's header for why). On this deployed site that's the Cloudflare Worker automatically; opened as a local file instead, run python refresh_server.py in this folder first. Results are cached server-side for 10 minutes; if a source is unavailable that field is left for manual entry.

The muted purple band is COMEX gold futures (GC=F, closely tracks spot) fetched from Yahoo Finance — background context, since both Costco's price and CollectPure's bid move with it. The blue line is your logged Costco price. Green is CollectPure's bid — every refresh logs a new reading rather than overwriting the day's earlier one; a day with a meaningful swing between readings (≥0.15%) draws as a box-and-whisker, otherwise it's just a point, so near-flat days don't turn into wide, hard-to-read boxes. The y-axis zooms to whatever's actually visible in the selected range, not a fixed scale, so small moves stay legible.

Premium % = (Costco price − CollectPure bid) / Costco price. Net margin % = Total rebate% − Premium% − CollectPure fee%. Rebate tiers assume Costco Executive Membership's 2% annual reward (capped at $1,250/yr on $62,500 of qualifying spend — paid later as a Costco Cash Card, not instant) stacked with a 1.5% / 2.0% / 2.5% cashback credit card. Margins now include the CollectPure fee entered per row, but still exclude shipping/insurance to sell and sales tax where applicable.

Sums every entry's "your card margin" dollar figure — the same number shown per row in the Log above — assuming 1 bar per entry, using whichever card/rate/fee was set on that entry. Log a separate entry for each bar if you bought more than one at once. Not a running cash balance, just a total of estimated/ realized margin across everything logged.