Broke Up With My Friend Over $30 💟

My friend's house was on the way to school, so I used to give them a ride every morning. I didn't mind doing it once or twice, but since they started riding with me every day, I started thinking about the gas and maintenance costs. So, a few days ago, I carefully said, "Hey! Since we're riding together every day, how about chipping in $30 a month? Honestly, that's way less than the round-trip bus fare, which is already over $30." But my friend got serious and said this! "Hey!! You're going that way anyway, isn't it a bit much to ask for money? Are you trying to extort money from your friend? That's really selfish." I gave them rides every morning, picking them up right at their door so they wouldn't be late, and treating them comfortably, but they made me out to be a money-crazed person just for asking for $30. I was so fed up that I shot back, "Fine, from tomorrow on, pay for your own taxi and ride comfortably." Is it the right thing to do to cut off a friend who calls me selfish for being stingy about $30 while getting free rides in my car?