[Xbox/PC] 1 Month Xbox Game Pass Ultimate $1 (Stacks Onto Current Subscription) @ Microsoft
However, it seems like if you have an active subscription of Xbox Live Gold, activating this deal will give you an extra month on your subscription, plus it will give you the Xbox Game Pass up until that date according to commenters in Chollometro.
The purchase of Xbox Game Pass Ultimate automatically upgrades your Xbox Live Gold and Xbox Game Pass memberships.
From what I can tell so far, if you want to take up this offer it might be worthwhile extending your Xbox Live / Xbox Game Pass membership before taking up the offer. As the conversion after taking up this offer seems to be worse than before taking up the offer.
You can recharge up to a maximum of 36 months.
Get all the benefits of Xbox Live Gold, plus over 100 high-quality console and PC games for one low monthly price. With games added all the time, there’s always something new to play. With a huge variety of games from every genre, there’s something for everyone. Enjoy exclusive member deals and discounts. Play together with friends on the most advanced multiplayer network and discover your next favourite game.
Use your active Xbox Game Pass Ultimate plan membership to play games on Xbox One and Windows 10 PC. The Ultimate plan includes the Xbox Game Pass Console Games plan, the Xbox Game Pass PC Games plan (Xbox Game Pass PC Games plan not available in South Korea and Turkey) and Xbox Live Gold.
Note: Purchase of the Ultimate plan automatically upgrades your existing Xbox Live Gold or Xbox Game Pass membership(s) to Ultimate at a conversion ratio each based on days remaining. Learn how this works at www.xbox.com/gamepass. Future code redemptions are also subject to a conversion ratio. Conversion ratio subject to change. All conversions to Ultimate are final: Once converted, you cannot re-convert your Ultimate membership back to a previous membership. Maximum 36 months of redeemed Ultimate per account at a time, including any converted time from Xbox Live Gold and/or Xbox Game Pass (for PC or console).
20 New Titles have also been released for the Xbox Game Pass:
Hollow Knight: Voidheart
Old Man's Journey
Shenmue I & II
Smoke and Sacrifice
Steamworld Dig 2
Wizard of Legend
Sunset Overdrive (PC)
As always, enjoy!