I was really hoping this wouldn't degrade into a discussion of economics. Having published numerous articles over the years dealing with economics in professional publications (not photography publications, obviously) in a former life it's often sad when I see people start trying to address the subject.
WRT prices being higher when the exchange rate was weaker, keep in mind that prices are set for products months in advance. Look at what happened when the exchange rate strengthened and people were up in arms because book prices were way out of sync. Businesses (producers) can, if they desire, make special pricing adjustments through rebates or credits to retailers which they can demand retailers pass on to customers but if this doesn't happen then there's nothing the retailer or consumer can do. The retailer can decide to lower its profit margins but isn't compelled to do so. The business cycle, unfortunately, doesn't react as quickly as the markets can. Further, to suggest that prices were about right when the CAD was at $1.50 is flat out incorrect (see below paragraph on PPP). I've saved literally thousands of dollars over the years buying bodies, lenses and other sundry gear (less on bodies, more on lenses) from the U.S. when the CAD was weaker and that's after factoring in exchange rate differences, shipping costs and taxes.
PPP really doesn't play a part either. PPP theory is based on a basket of common goods that are traded and consumed by a broad sector of a population across countries. PPP theory doesn't necessarily hold for highly specialised goods which photography gear would be considered as. There's also no set definition of what the 'basket' of goods should be so PPP is nothing more than an estimate rather than a hard and fast number. Additionally, PPP is a long term indicator and is not intended to be used as an indicator for shorter term fluctuations and volatility. When we talk 'long term' in economics, we're talking about 15, 20 or more years. There are also two forms of PPP; absolute and relative. Absolute PPP deals with absolute price differences. Relative PPP deals with inflation and rates of change of prices.