Most (if not all) neighborhoods have Saturday parking restrictions. Public Transit (for 1) is going to cost you $4+ RT. Your safest parking option is to buy BART extended parking but you might be at a $5 to $6 RT for the transit, plus $5 a day for the space. Seriously, you're in the "save your $ by ordering a couple of fewer drinks and don't be stupid with your car" arena now. You're adding hours, risk, unfamiliar areas, and stress to save under $100 when you are staying at the Hilton Union Square, not the Western Addition Roach Motel. No, it isn't my $, but you did ask for our advice. "Honey, I lost the car on 47th Ave. and the N Judah broke down" isn't a conversation you want to have during your vacation.