Do employers see a difference between an economics or a psychology major?

Do whichever is cheaper. Most employers don't really care about your U-grad major PROVIDED you show good internship/work experience for any particular roles. So stretching out another year just to finish w/ a BS in Econ could be superfluous and expensive. However, if you don't really have any relevant knowledge or work experience-basically anything to show that you're up to speed on financial markets and/or quantitative methods, then you might consider it. I was in Corp Finance close to a decade and interviewed/saw plenty of poli sci and english majors with superior Excel skills and internships who got hired over Business/econ/finance majors with nada (Acctg majors would usually beat most folks out though, in my experience. Their resumes and internships tended to show better alignment w/ specific FP&A roles)

As for the Mfin...how long a commitment would that be? What type of prerequisites would that entail given you've majored in Psych? I'd be more concerned about gaining actual work experience-even for just a yr or 2-before investing more in advanced degrees just yet. People I know who went on to get Mfins were usually sponsored or obtained them part time while working to bang out promotions.

But this is all conjecture. We'd need more info on your profile regarding your experiences and specific short term goals.