Bottle cages don't change much from year to year. Lights are going through a rapid development phase so that the expensive light from 5 to 10 years ago is hopelessly out of date. Even the "cheap" $80 Magicshine I rode 5 or 6 years ago had a lower output than the $20 Magicshine clones you can get today.

I have no problem spending money on quality bike parts but I'm not a fan of spending money on bike parts that will rapidly go out of date. If something comes along that is a radical improvement over existing technology...threadless headsets, suspension forks and external bottom brackets, for example...I'm an early adopter. If it's only a marginal improvement...like disc brakes, dual suspension and >8 speed drivetrains...I'm much slower to adopt.

There are somethings that I won't adopt at all, like U-brakes (I was right that they were a total disaster), 29er mountain bikes and junk saver saddles. Those don't make anything better.

I'm still waiting, by the way, for any LED light that could match my old overvolted MR16 halogen lights.