When we look at some of Canon's current lenses, such as the 50/1.4, we can see that they either are or are approaching being 20 years old and that their price hasn't changed a whole lot in that time. However in the last 20 years, lots of other things have had rather dramatic price changes, for example houses and cards and last but not least, wages have gone up.
What that makes me wonder is in 10 or 15 years time, will the prices of these new primes with IS still be considered to be "high" or will they have moderated if the price stays the same but our take home salary has increased?
Is Canon delivering new lenses at a higher price with the expectation that they will remain on sale for close to 20 years and that if the price doesn't change then as they approach end-of-life, they will have become as affordable as the current lenses are today?
Is an $800 lens today a $400 lens (in terms of affordability) in 20 years?
Something that I just realised is that Canon have to replace or retire a lens within 26 years of its first manufacturing date as their date code system does not have a way to handle it wrapping.