This question already has an answer here:
After my interview, came my first day of employment, but with no previous information about the position's benefits nor responsibilities.
Now, the first day is done; and the benefits and salary are just offered "verbally"; I wanted to "negotiate" the salary, but the hiring person showed almost no will to increase the salary.(conversation ended here)
the contract would be signed after a month. I asked for the benefits and responsibilities emailed to me (not received yet).
Would be appropriate to negotiate it again after failing that on the first day?
(probably after considering their detailed email about the position)
Would it be good to mention a good job offer I received for a similar position?
(I really did and it's 30% higher salary)
or would it work better to wait until the contract is to be signed?