If a 2,300g wheelset, saddle that costs $10 new at full retail, and a $30 brake set are found on a $2,000 bike let me ask you this:
If those parts aren't junk then what is? If you go much cheaper they'll be free and wheels much heavier don't really exist.
Also, if that's on a $2k bike, what do they put on a $600 bike?