As others said, it depends on the lift.
Even a budget boost takes time: lift the vehicle, pull the tires, support the axles, unbolt the shocks, drop the axles, pull the springs, insert the bump stops, insert the spacers, reinsert the springs, install new shocks, install trackbar relocation brackets, reinstall the tires, lower the vehicle, torque everything down, do a course alignment, road test, final alignment, final road test, recheck bolt torques, pack-up your original parts, clean-up and paperwork. That sounds like 2 guys working 2 hours plus a go on the alignment rack. At $80/hour, that's $320 labor + $80 for the final alignment.
If you're swapping out control arms, brake lines, new adjustable track bars, I'd say $400 was dirt cheap.
I'm a JKO Reject