Offering your customers the absolute best "bang for the buck" is great.
However, you HAVE to recognize that 99% of your customers (at least) in a retail shop aren't even going to know what "technical aspects" of a product they should be looking for, and therefore won't understand why an XXX is worth a lot of money.
They also will be on-guard, due to experiences with other salespeople (car audio and otherwise -but I gaurantee your local shops haven't helped the stereotype any), and won't just believe anything you tell them - and trying to discuss and explain technical product aspects is very likely to sound like greek to them - and interpreted by them as your actually being DIShonest (ironic as that may sound)...
...rather like the old mechanic story "Uh yeah... I need to charge you $150 to replace your blinker fluid reservoir, and your muffler bearings are looking pretty bad too, might take a couple hours of labor to grease those - but you know, no other shop would even try to tackle these tough jobs!"
Sad - but true.
