There's no need to be a jerk, buttface, pigheaded, rude or otherwise to those that work there and striving to help your critical concerns about a $15 bag. I don't get defensive normally with my children. I like that they experience difficulties in life and realize how it really is...
HOWEVER, one would think that someone in Utah County amidst a people that largely consider themselves Christians to be at least reasonable, if not somewhat kind here or there. It's amazing the stories I hear from my daughter about the extent of rude, insane behavior, much of which based on the fact patterns it sounds like people don't even realize they are as big of jerks as they actually are.
I know this board is filled mostly with fellas that haven't likely stepped into retail locations like TJ Maxx in years, but in your family discussions, please convey to your families to be more self-aware of how you interact with others and try, just try to be as Christian as you profess to be on Sundays. Seriously.