In the 90's the wife and I were traveling and ended up stuck for 12hrs in Istanbul International Airport (flight out was continuously delayed for 2 hours at a time). Then, and I assume now in Turkey, you negotiated the price of everything. I was told it was a cultural thing and refusing to negotiate was considered rude, basically akin to "I would rather pay more not to interact with you". Anyways, around hour 4 I decided I needed a coffee from the airport cafe/cafeteria, I got my coffee and politely haggled with the lady cashier... I ended up on 35 lire... fine (like 50cents at the time)
Several hours later, I needed another cup of coffee, this time there was a local in line before me getting coffee too. He negotiated 25 lire, so when I got to the cashier, she smiled and I started at 20 lire, she said no, we already agreed on your price 35 lire. She wouldn't budge and I needed the coffee so I paid it begrudgingly. I'm still pissed and we're talking about 5 cents... It's petty, I know, but it is what it is.