Halldin & Co

A coarse, dateless secondary signal -- current medians only, not a history, so shown as plain tables rather than charts. Shape/color/ clarity impact tables are natural-only (this source has zero lab-grown or colored/fancy coverage there).

Your average purchase price per diamond_type (parcels excluded -- a parcel's price isn't a single-stone price, same reasoning as the reference-index lookup above) against both market signals this project tracks. A positive difference means you paid more than that signal on average; negative means you paid less.

A real, dated snapshot explicitly sourced from the industry-standard Rapaport price list -- confirmed by direct verification against a rival "wholesale" source (Diamond Registry) that turned out to have a fabricated calculator and internally inconsistent numbers, and was ruled out. Deliberately narrow, not stretched: this grid only covers the 1.00-1.49ct bracket (color D-M, clarity IF-I3) -- carat outside that range has no wholesale figure anywhere in this app, on purpose, rather than an extrapolated guess.

Coarser than the grid above -- per-carat-weight price ranges with no color/clarity breakdown, from the same page. Informational only, never wired into any per-stone estimate in this app.

Real average asking prices by shape and carat weight, from stones actually synced via "Sync Whiteflash Prices" (Inventory tab) -- builds up over several syncs, not fetched all at once. Treated as a wholesale/cost-basis reference in this app, not a retail target (see valuation.py's naming note) -- never wired into suggested_sale_price_eur, purely informational. A blank cell means no real listing has been synced for that shape/carat point yet, not a zero. Natural coverage on this source is heavily Round-dominated (confirmed real: 337 of 341 branded natural listings are Round) -- other natural shapes may stay sparse or empty even after several syncs. Lab-grown has broader real shape coverage.

Real average asking prices by shape and carat weight, from stones actually synced via "Sync Blue Nile Prices" (Inventory tab). Treated as a wholesale/cost-basis reference here too, never wired into suggested_sale_price_eur. Coverage is real but narrow by construction: robots.txt only allows crawling the ~32 diamonds server-rendered per shape category page (real pagination is driven by a disallowed API) -- confirmed, not a bug -- so this is roughly 32 stones per shape (10 natural shapes + one mixed-shape lab-grown category), not the site's full catalog. A blank cell means no real listing has been synced for that shape/carat point yet, not a zero.