I got laid off in January and am still getting my hair cut and colored (I get a semi-permanent gloss) which is about $150 every eight weeks. I get my nails done every three weeks or so ($100 altogether).
I don't get botox or any other treatments, really.
I'm freelancing now and my spouse still has a job (knock wood a million times) so am not totally without income. If I were, I'd find a way to stretch out the hair appointments and would probably stop manicures (but not pedicures, unless I absolutely had to - I live in the south so in open-toed shoes year-round, and am rough on my feet).
I think it really just depends on how tight your finances are, what you do now. And yeah if you're job hunting it's probably a good idea to try to keep your looks up.
I wouldn't dye my hair myself. I'd sooner just let some grey come in, I think. Unless I am really misunderstanding how good/bad box hair dye is.