When Did $5 Become $10?

I thought today might be my lucky day.  Upon checking out at an unnamed local grocery store, I was handed my change of $7.77.  "Well, this must be a sign," I thought.  So, I made my way over to the service desk to by a Powerball ticket.  My luck soon turned sour and I got a lesson in counting money.

Me: "I'll have a five-dollar Powerball, please."

Her: "That will be $10."

Me: "I don't have $10 cash, that's why I want a five-dollar Powerball"

Her: "They are $2 per play now."

Me: "OK, then I'll just take a six-dollar Powerball."

Her: "That will be $12."

Me: "OK, we're not on the same page here.  What if I'd like to buy 3 plays for Powerball."

Her: "That'll be $6."

Me: "There you go."

Not sure why I felt stupid as a part of that conversation, but last time I checked a dollar was a dollar.  This conversation could have ended so easy by her simply telling me that I could only buy in even numbers.  I really wish I had more cash, because then I could have made her give me back change, and by her logic, $7 change is really $14.  Geez, I hope I win this lottery, because my $110 Million could be $220 Million!