Is a $200+ 3M or Humanscale-style tray worth it over a $50 clamp-on?

For occasional typing, no. For 8-hour-a-day knowledge workers with existing wrist or shoulder issues, specialist ergonomics communities consistently say yes, citing the wider adjustment range, real negative tilt, lift-to-adjust mechanisms, and dramatically better durability. The premium trays are the ones reviewers describe as outlasting the desk they're bolted to.