CDKeys offers GOG downloads of The Witcher 3: Wild Hunt Game of the Year Edition for Windows for $26.99. That's $3 below our mention from two weeks ago and the lowest price we've seen. (It's the best deal now by $2, although most retailers charge $50.) It includes the base game, the Hearts of Stone and Blood and Wine expansion packs, full soundtracks, and all post-release DLC.
Note: New customers can provide an email address on the CDKeys Facebook page to get a unique coupon code that cuts an extra 5% off.