You got the salesman upselling part right. I have seen some darn good salesmen not know crap about the phone and still sale it.
If you come into one of the 300 Cellular Sales locations....ha their salesmen will sale mostly everyone walking in the door! Those who like Verizon: Check them out. They're based out of Knoxville, Tenn originally and they make more than Verizon Corporate stores in their locations, shutting corporate stores down constantly in their regions.
That's who we worked for, now moving to MO and starting another company. Hope they are as good!