Is Ms Sarah Bélanger Demaneuf telling 'rude' customer that she wont sell the 50 cent ornament for 25 cent as "we weren't at a yard sale", clever, 'anti-grinch' or lowest level arrogance?

Ms Bélanger Demaneuf told her that it wasn't possible to sell it for her requested price of 25 cent as "we weren't at a yard sale".

This woman from Alabama shared her delightfully petty revenge in a now viral Facebook post. Let's cast our minds back to 2001 when Sarah Bélanger Demaneuf was working in retail for an unnamed company and a customer wanted a further reduction on an item already for sale - for 50 cent. 

Her Facebook post reads:

"I just can’t get into the holiday spirit until I post this. Have a vengeful Christmas y’all!!
The Star of Vengeance
This is my favorite Christmas ornament, but rather than symbolize peace and goodwill, as it should, it symbolizes vengeance and spite.

I was working at a local retail store after Christmas and all of our ornaments were reduced to 75% off. This little star was .50 cents. A terrible woman (dressed to the nines and driving a high-end Lexus, so pretty well off) came into the store and wanted 4 star ornaments, but wanted to only pay .25 cents a piece. As we weren't at a yard sale I said no and she started arguing with me, becoming increasingly rude and belligerent. After not bullying me into caving she said "Fine! My friend works at the other store in Huntsville and she told me that all the ornaments will be 90% off tomorrow, so I'll just come back in the morning. "I can't guarantee they'll still be here," I said. And the jerk said, "There are 12 in the store. No one is going to buy all 12. I'll get what I want, prepare to feel stupid tomorrow."
So in an anti grinch moment my heart shrank 3 sizes and I bought all 12 star ornaments. I then called the other Huntsville store and bought ALL their ornaments. And just to be extra spiteful I bought all the star ornaments in Decatur and Florence. It was the most vengeful $30 I ever spent.
The next morning she was at the store as soon as we had opened. I had the pleasure of telling her that ALL of the star ornaments in North Alabama had been sold to one customer. The look on her face was worth every penny spent.
For years I gave the ornaments to friends and family, but I saved just one for myself.
17 years later, I still smile when I hang it on my tree."

So is she clever, or 'anti-grinch' or lowest level arrogant lady who just didnt deserve to face customers as she was never good at managing customers... just my opinion on her public post...