trackball mouse gets you the x-y. Force sensor could get you the z. You get also the rotation and tilt, see page 4 in the manual

https://3dconnexion.com/manuals/spacemouse-wireless/en/Manua...

But yeah pricing is based on value not cost I guess. People who need it (architects, 3d designers, mechanical engineers) often have high end workstations so price of the mouse is a rounding error (and like 1 hour of their salary?)