Great advice on going for the lowest (cents) so you can work with integers. I do something similar with dates on all my apps where I go for ints in the database and always save unix timestamps. I can't stand dates unless I'm working with timestamps.
Same! Dates are one of the biggest sources of programmer error in my experience, and representing them as ints until they are rendered to a UI prevents a lot of it.
Actually, using timestamps for all dates is a bit like using floats for currency. For many cases it doesn't matter, but you lose information.