someone else replied and then deleted their comment, but i think they made an interesting point that i don't agree with.

they said that someone desperate to get a job will accept a low offer and keep looking for something better. and by asking them for their expectation this could be prevented.

if i am desperate for a job then i am going to give you a lower expected number in the hopes that i'll get the job and then keep looking anyways.

so no, i don't think asking a desperate candidate will help you avoid that problem.