The only thing I do want to bring up about shopping locally, for electronic components specifically, is that stores like Radioshack are essentially extinct, at least where I am in the Midwest. There are no local electronic stores of any variation except for Best Buy.
Which is precisely why I do not shop at corporate mega stores that make it impossible for smaller businesses to compete using shady practices to lower prices.
Once Amazon or Wal-Mart are the only company left, they will be free to raise the prices to whatever they want.