Would like some input on this so please read!

Tonight one of mine and my husbands best friends came over with his new girlfriend of 3 weeks. We've met her before, but tonight we invited them over for supper. I cooked a huge meal and had everything on the table for everyone to fix their plate. In my salad bowl I had these really cute salad spoon, she complimented me on it and said "I love this, matches your kitchen perfect!, where did you get it?" I said dollar general, which is where I found it. I love that store! She literally threw it down and screamed "are you kidding me?!?" I said no???? Pretty confused, I asked what was wrong. She proceeded to tell me how that was gross and how she would never touch food with something from there and so cheap.. I was mortified. She then asked where my plates, bowls and saucers came from. I said Walmart.. Which might I add they are the really nice plates.. The $90 set that comes with plates, saucers, bowls and cups. (We're from Arkansas, everything we own comes from there lol) to me, $90 is a lot for plates.. She refused to eat anything on them!! So I went into the kitchen and got another plate, one of those really cute blue and brown marbled plates (also from Walmart in one of those $90 sets) she asked where it came from, I said Kirklands (one of the really highend stores here) she had NO problem eating then! After we finished, she said you really need to invest in more expensive dinner wear. Food tasted so much better off the plate from Kirklands.. I said that's funny, that plate was from Walmart also... She became livid and tried to make our friend leave.. He was so embarrassed by her and pretty mad.. He said, I don't see why you have such a problem eating off that plate.. The plates you eat off of at my house probably came from yard sales or walmart.. She pretended to gag and get sick to her stomach, called her mom and told her about the horrible evening we made her go through.. We could hear her mom throwing a fit over the phone and demanded our friend to take her home now! He said, since your on the phone with her.. Tell her to come get you. We're done... 

I'm still so confused as to why a person would be raised that way. Is there more people like that out there? 

What's your  opinion on this?

Btw, the red plate was the first plate she had a problem with... The blue and brown was the one she thought was from the highend store.. Hahaha i don't see anything wrong with my plates!