"我们在退休后需要维持的收入会大幅减少"
I don't agree "大幅减少". When you get older, you may have health problems, you may need support worker come to your home to assitant your daily life. This expense is not cheap.
For 2010 OAS, if you live Canada for 40 years, the max amont is 6222.15
To qualify old age security...