Also, not to poo poo, but if you've got 900 miles in 4 months...it'll take 55 years to accumulate enough points for 1 business class ticket. Assuming my math is right.

900*3 (trimesters) = 2700
150,000 (J class Canada-Asia 1) / 2700 = 55.55

That's forgetting any devaluation and only 1 ticket.

If you REALLY decide this is for you, then you need to get the credit card for some quick big bonuses that'll shave 40 years if you can grab 60,000-75,000 signup miles. Then use those cards to buy everything to ramp up your earning. I put everything on my credit card and only earn around 2,000 miles a month. The real miles (outside of bonuses) still come from flying, and flying lots.