It's not actually an offer. It's an automatic 'entitlement', as no acceptance is required.

I'm not sure how the overlap works though. The $1 one is still current, but so is the 50c one.

I'm in a similar boat to you. The bulk of my items are less than $10, so any payment for subtitles, which I don't really need for books, is a direct hit to my bottom line. And I suspect that THAT charge would be monthly, not for the life of the listing.