Sorry Silly - I can't agree with this. Cambridge Audio are sold exclusively by one of the biggest hifi box shifters and yet the secondhand value of their kit seems to stay high. I had a 6-year old A5 amp, that went for 60% of the current new retail value about 6 months ago, and other CA stuff seems to hold it's value.
Don't get me wrong, Naim and similar gear does hold it's value well, but I think that's down to reviews in the popular media (that reflect the quality of the kit itself) rather than price fixing.