I don't find that at all correct for my area (Austin, TX). Most places sell both - upper and lower end places.
I think they just wanted you to buy what they had, and tried to tell you whatever they needed to in order to get your business. Maybe it's time to seriously consider finding another shop. One, because they made you uncomfortable and two, because you now know they aren't honest! (And if they lie about such a simple thing, what else might they say?)
Sorry this happened to you. That's really sad!
Debbie in Austin