My GPA was 2.37 and I would've had to take so many classes to increase my GPA up to the cut off point of 2.7 (B-). With 90 credits worth of classes, you'd need 90 credits at 3.0 (B average) to make up for the difference, or less if you get better grades and that means you're on the low end of what they accept.

Now I presume if you did 2-3 semester with a B+/A- GPA, they would take that as testifying you can handle the masters and let you in, however I'm enjoying math way too much right now and there are several classes (Algebra 1-3, Topology, Differential Equations and several classes in statistics I intend to pick in the option block) that will come in handy if I head into ML masters I'm also interested in Type Theory and all of Discrete Mathematics. Also, I feel math is a great program to improve at general problem-solving.

The first semester was really challenging, some classes I had in fact already done (Calculus 1 and Linear Algebra) turned out to be surprisingly difficult. I'd say around halfway through the second semester I felt I had gotten my younger brain back.

I don't have expensive habits, have two restaurants meal a week, own a car and live at the university residences (rent is 390$/month, parking 850/year). My cost of life seems to be around 12k CAD/year and am Canadian (tuition costs are 1600/semester) so I really have no idea how much you'd have to have saved up if you are in the USA.