More about the thrift store

When I was in the thrift store, I got the Mackay book and 4 others. 5 books in all. I went to the checkout counter, Discover Card in hand. Had no cash on hand at the time. The pre-sales-tax total, as figured in my head, should have been $1.50 or so for all five books.
The lady didn't feel like ringing up my stuff, so she told me, in bare minimum English, "10 cents each."
So, I was like "ok, cool thanks!"
I gave her my Discover Card. Never before in my life have I seen as sudden a shift in moods!
She yells at me "Don't you have 50 cents in your pocket!?!?"
and politely I said, "No, if I did, I would use that."
So she yells back at me (still in miniscule English) , "It costs us $1.30 just to swipe a Visa Card!!!"...
To which I not-so-wisely-and-without-thinkng-before-I-reacted said back to her, "That's ok. It's not a Visa Card, it's Discover, it pays CASH BACK"...I am still smiling at this point, if even just because it's forced.
And she yells back at me, "Just take the damn things! Pay when you're here next time!"
At this point, I told her, "Ok, thank you very much."
I walked out feeling both sheepish and triumphant at the same time. Very strange combination.
As I was exiting the building, I held the door for an elderly gentleman who was strolling in for some last-minute stuff before the store shut down for the day.
He said "thank you, son!"
and I said, "You're very welcome. By the way, this may be of benefit to you. But I just found out they take Discover cards in here!"
and I was laughing as I drove off...