"What's your best Price?"

A few years ago I was selling a clean low mileage Neon, I had a decent price on the window with all the necessary information pluss I said no texts after my phone number.

Of course I get texts one in particular was insistent, asking questions and wasting my time finally asking for my best price so I told him the number that was 500 higher than I had on the car. He squealed and I told him the 500 was for making me text.
I didn't hear from him again.
Your best price can always go up! Best for me or best for you?