please answer my question

Hi. I wanted to know if graphing calculator is necessary for sat maths 2 for 800 score. I have never used a graphing or a scientific one before. also i am planning to do major in finance or related to finance. Will it be of use in that field? The ultimate question is…will it be worth for me to spend so much on it?
please let me if you have any doubts in the question and i am open to all suggestions