The truth is that equipment upgrades seldom make economic sense. Bicycle manufacturers can buy everything much cheaper than you can. So much so that I've known guys to buy a whole brand new bike just to move the components to another frame. As a general rule, you can buy a new bike for less than you will spend obtain similar quality components.

For lots of guys like me, however, there's more to it than just the economics. We get a degree of satisfaction by doing it ourselves. For us, economics isn't such a big deal because those same components are likely to get shuttled from bike to bike for years.

I think that there's a third group too. That would be the shoppers. They claim that by carefully shopping the internet and maybe ebay they can acquire components for near manufacturer prices. I suspect this group gains their satisfaction from the purchasing process.

Figure out which group you belong in and have at it.