Edge cases, single-SKU starter brand ($50k/mo) vs multi-brand house ($5M+/mo)?

Two very different builds; both are reasonable on Magento but the architecture diverges sharply.

Single-SKU starter ($50k/mo, e.g. one greens powder, one collagen, one nootropic):

• Honestly, you might be better on Shopify Plus + ReCharge if you don’t need custom COA / lot tracking. The per-tx fees are tolerable at $50k/mo (~$1.4k/mo). Magento becomes worth it once you have $1M+ GMV and want to escape the SaaS bleed.
• If you do pick Magento at this scale: keep it lean. 1 SKU as configurable for size (30ct / 60ct / 90ct), Skio or Bold for subs, Octane AI quiz, Klaviyo, Yotpo for reviews, Smile for loyalty. No COA module (yet), DSHEA disclaimer + regex flagger, single sales channel (Amazon).
• Total build: $4,999 fixed-fee, 6 weeks. ~$600/mo total platform + apps cost. Built to grow into a multi-SKU brand without re-platforming.

Multi-brand house ($5M+/mo, e.g. 4 sister brands sharing a parent company):

• Magento crushes Shopify at this scale because you get a single instance with 4 store views, shared inventory pool, shared customer database, shared loyalty program (or separate, your choice). Shopify forces you into 4 separate Plus subscriptions (~$8k/mo just in platform fees) plus duplicate apps.
• Architecture: multi-store, multi-website. Each brand has its own URL, branding, checkout. Shared admin, shared customer data warehouse (or segmented, configurable). Shared inventory across brands if SKUs overlap.
• Custom subscription engine (vs SaaS) usually pays off above $5M sub GMV, you save $60k, $120k/yr in fees.
• Full COA + lot-traceability with WMS integration (NetSuite WMS, ShipBob, ShipHero, Manhattan SCALE). FDA cGMP 21 CFR 111 audit prep usually in scope.
• 5+ channels via Channable or Feedonomics. Practitioner / B2B layer possible (Thorne pattern).
• Total build: $25k, $120k depending on scope. 14-24 weeks. Ongoing retainer $5k, $15k/mo.

Where most supplement brands get stuck: they’re at $1M, $3M GMV, outgrowing Shopify variant limits or app-fee accumulation, but not yet enterprise. That’s the sweet spot for the $4,999 Magento build, you ship in 6 weeks, save $40k, $80k/yr in fees, and the architecture grows with you for the next 3-5 years.