Assuming car ownership is mandatory for you:
250/mo = $3,000 a year for a parking spot.
1 $90 ticket a month + 1 $500 tow a year + $150 a year fee + 1 broken window a year at $200 = $1930 a year for street parking. Unexpected, irregular, bad things weigh more heavily on us mentally than expect, regular, drains. You'll FEEL like you are spending more on parking tickets, towing and new windows.
I guess I'd ask your neighbors how often their cars are broken in to. I think in densely populated neighborhoods where $300 can be charged for parking, it is probably substantially less than once a year, and more like once every 3-5 years. But, even assuming you get a ticket every month, get towed once a year, and have your car broken into every year, you'd save $1000 a year by parking on the street. If you are really diligent, and don't get towed and only get 6 tickets a year, and a broken window every other year, you'd save over $2,000 per year on average. That probably pays for all of your winter skiing or a new $8,000 car every 4 years!