I was a bit unsure whether this question belonged here, but after finding many questions requesting advice with respect to mathematics studies I decided to go ahead.

Over the last year I have developed a strong interest in mathematics and would like to pursue it at the university level. The long-term goal is graduate studies. 

My original intent was to first pursue a B.Sc in mathematics. I had met with the undergraduate coordinator at a university I would like to enrol in and he recommended that based upon my background that I may be better off pursuing a masters degree with a qualifying year comprised of advanced undergraduate courses.

My background is: 

* Degrees: B.Comm (Economics), M.A. (Economics)
* Mathematical Courses: Business Calculus, Mathematics for Economists (includes calculus, linear algebra, set theory, optimization, topology), Introductory Statistics, Econometrics
* Research Experience: Four RAships, two upcoming publications (not in mathematics)
* Self-study: *Calculus* (Stewart), *Linear Algebra* (Strang), Currently working on: *A Course of Pure Mathematics* (Hardy)

I would like to ask that given an individual with a background in a quantitative field, what are the pros and cons with pursuing either of these options.