what is the dollar amount that I can bring over the border after a 48 hour absence from Canada?

Answer 1

I will assume you are asking how much money value of purchases you can bring back after 48 hours. The answer is $400 per person. It was recently raised from $200. I don't have the exact link, and some of the old links haven't been updated yet to reflect the change.

Answer 2

There is no limit to the amount of money you take in or out of Canada, however, you are supposed to declare any amounts over $10,000 Canadian: http://www.cbsa-asfc.gc.ca/general/cmr/menu-e.html