I'm not so sure too much has changed since I got into the sport. In 1991 I bought an S-Works FSR for $5200. Using the BOC inflation calculator that comes to $8059. That bike was a complete, non custom bike that had some specialized house components on it (like that sweet 120mm polished Ti stem) and the Specialized Carbon "mag 21" fork. At the time you could easily have added a great deal to the cost by adding some Chris King bling, or perhaps some Ringle anodized parts and ceramic rims and got that sucker up to $6400 easily, and BAM, there's your $10K bike in today's dollars. Adding discs (I think there was one option and it was not hayes yet) would have pushed that price drastically more skyward.
Let's also factor in that in 1991 the USD to CAD was 87c rather than 75c, and you don't even need to bling it out to get close to $10K.
I don't think much has changed. Apart from the fact that a $4600 bike today ($3000 in 1991 dollars) is a mighty fine dual suspension bike, whereas $3K in '91 got you a steaming pile of shit dually, or a nice full rigid.
Let's also ponder my $440 purchase of dual beam 32 watt halogen Niteriders which is $681 today.
I think what we can learn from all of this, is that I was a fool with my money just as much when I was 21 as I was until I started reading Mr Money Mustache last week thanks to Heckler. For sale ads are pending. Time to downsize.