Whats in a name

My mum wasn't feeling too well this morning so i accompanied her to see a doc at Clementi Central and we went for breakfast after that. Never one to miss the chance to eat the very good Wanton/Shui Jiao Noodle(Boon Kee), we ordered 2 servings and prepared $4.40 to pay the good uncle.

But he said they have 'tiao2 zheng3'ed the price and each plate costs $2.50 now.

i think the noodles are worth the $2.50 and there's nothing funny there.
It's the 'tiao2 zheng3' which i find funny.
Whats this officialgahmenlingospeak doing at my heartland "hawker centre"!!