An elderly man approaches the counter in a drugstore in midtown Manhattan. He seems to be Greek, or something Middle Eastern, or in any case not American. His clothes look a bit too old fashioned to be an American, and he is too uncertain of himself to be a world-weary New Yorker.
The store is fairly empty at this time of day, sometime in mid-afternoon on a weekday. There is only one bored cashier. The man is clutching a toothbrush.
"Excuse me Miss, how much?" he says, ever so politely, holding out the plastic packet. The bored girl takes it from him and scans the barcode.
"It's a buck and a quarter" she say, shifting the gum in her mouth. "You wanna buy it?" A look of confusion crosses his face as he looks at her inquisitively.
She does not do a good job in suppressing a sigh of impatience, though she has no other customer to serve. She points wordlessly to the display on the cash register. His face clears. He understands now. He purchases the toothbrush, takes it and the receipt, thanks her to the back of her head, and shuffles out.
And the point is...?
Idioms are very hard to understand for non-native speakers. People who aren't used to communicating with different people don't get this, and English speakers are, from what I've seen, the worst. They aren't trying to be inconsiderate, but the result is a confused listener. It doesn't take any more effort to say "a dollar twenty-five", or even "one twenty five", which is far easier to understand.