I don't understand why someone would ever waste their time (and money) on building something as impractical as an alt. bike...just kidding, but hopefully you can see how this whole debate can be easily turned around on just about anything.

For the record, I do own an almost $4k bike (paid for with a well earned bonus from my employer) and it's the sweetest thing I've ever straddled. Most days I ride my $300 MTB to work though.