Interesting idea Im checking it from Japan with my system language set to Japanese, but the product descriptions are still showing up in English. The platform UI itself seems to be localized, so this might be a bug.

As for the token costs, have you looked at Gemini 3.1 Flash-Lite (preview)? The quality is solid and it's dirt cheap: $0.25 per 1M input and $1.50 per 1M output. Unless you have massive traffic, it would probably only cost a few dollars a month. Seems like a very reasonable overhead for the value it adds

i18n is far easier to build in early and with a Claude hook, is trivial to keep up with. A lot depends on how far you go with multilingual support.