Tilapia fillets, frozen price in Boston.

How we got these numbers

• Instacart — Aldi:Category multiplier against Walmart base, adjusted for Northeast Urban ($5.34)
• Walmart+:Regional baseline ($6.28)
• Amazon Fresh (Prime):Category multiplier against Walmart base, adjusted for Northeast Urban ($7.22)
• Instacart — Whole Foods:Category multiplier against Walmart base, adjusted for Northeast Urban ($10.36)

Live observations come from public weekly ads (Aldi, Whole Foods) and BLS Average Retail Food Prices, refreshed daily. Estimates use a per-category multiplier calibrated to NPR, Consumer Reports, and Tasting Table grocery comparison studies.

Why this category prices the way it does

Meat is the highest-variance category by retailer — Walmart's in-house meat program runs ~30% cheaper than Whole Foods' grass-fed/organic-leaning case for comparable cuts.

Boston grocery context

Boston's grocery scene is shaped by the local Stop & Shop (Ahold Delhaize), Star Market (Albertsons), Market Basket (cult favorite, not on Instacart), and Roche Bros. Wegmans has multiple Boston-area stores (Newton, Burlington, Medford) with strong local following. Aldi has dense MA coverage. Whole Foods has multiple Boston and Cambridge locations. The metro's narrow streets and college-density mean delivery vehicles often double-park briefly — building access varies hugely between Back Bay brownstones and South End apartments.

Boston shoppers consistently get the best value from Instacart-Aldi for staples. Add Wegmans-via-Instacart for produce and prepared foods — the Newton and Medford stores have wide same-day windows. For Cambridge and Somerville, Trader Joe's is the cheapest premium fill-in option.

Tilapia fillets, frozen prices in other cities

• New York City, NY
• Philadelphia, PA
• Washington, DC