The cost for Xbox Game Pass is as follows:
$9.99/month (First month $1) (PC)
$9.99/month (Console)
$14.99/month (First month $1) (PC + console)
Consoles must still purchase Internet access for online games through Xbox Live Gold, unless you're paying for Ultimate.
You do not need Xbox Live Gold if you need Cloud Storage; if you've got an Xbox account, you've already got it.
With Xbox Game Pass, you get access to Xbox's library from OG Xbox to Xbox Series X (albeit with a much smaller library than PS, but also albeit due to less bloat from clearance games), and if you pay for Ultimate, you also gain access to EA's entire library of games via EA Play.
Within this link is the list games Xbox Game Pass is adding and taking away, following the trend of previous months - 12 in/7 out in this instance (YMMV depending on if you use PC/xCloud or console).
Here's the current lineup of Xbox games if you're interested:
https://www.xbox.com/en-US/xbox-game-pass/games
You will also get a 10% discount on all Xbox games across all platforms (sans Steam for obvious reasons) with Ultimate, should you choose to actually purchase those games.
Be wary that you may still have connection issues even at recommended speed of 10 Mbps through a wired connection, loading in takes around 10-15 seconds, can have lag and frame dips dependent on the intensity of the game, and once the connection drops your session is over. However, you can suspend your game session to mitigate connection issues.
You can browse and play Xbox Game Pass games with a mouse and keyboard on both consoles and PC (so long as the publishers allow it and state it on the game's home screen) and can support any compatible controller (compatibility includes all Xbox Wireless Controller options and DualShock 4,
among others (USB and/or Bluetooth connection may vary dependent on the product).