Stack-tier pricing

Aurex's pricing ladder for every peptide SKU: - **MSRP** — strike-anchor reference price - **List** — the standard sticker price - **Sale** — current public price (the default everyone sees) - **Subscribe** — recurring delivery price (~10–15% off Sale) - **Stack-tier floor** — the absolute floor, unlocked when the cart contains 3 or more unique peptide vials (excluding accessories) When the stack-tier rule activates, every peptide line in the cart drops to its stackFloor price, and a "Stack pricing (N vials)" line appears in the summary. The discount stacks with the 8% crypto rail discount. Researchers who already plan to buy 3+ vials get the same per-kit economics as a curated /stacks bundle, without committing to one of the curated themes. The /stacks/build route is the explicit entry point for this flow.