What's the maintenance burden of a multi-store Magento?

Lower than running N separate Magentos — that’s the point. (1) One upgrade applies to all storefronts. (2) One extension stack to license & maintain. (3) One hosting bill (provided you sized it for the storefront count). (4) One admin login for your ops team. The catch: set up wrong, multi-store can become an n-by-n compatibility matrix every time you change something. That’s why we audit + diagram + scope-test before any code goes live, and bake regression tests for each storefront into the deploy pipeline. 30 days post-launch + retainer covers ongoing localisation.