$9.99 for a month of gamepass PC, or $10.99 for console (ultimate you’re paying for cloud access or online play, so it’s a disingenuous comparison) You can play starfield for a month, then buy it for 20% off through gamepass, so $55.99. $55.99+10.99 = $66.98.
So you basically get a $11 month-long trial, then $2 off the full price if you decide you like it enough to keep.