Although Southwest airlines is advertising fares as low as $59 each way (before taxes and fees), none of those fares appear to be available out of Oakland or San Jose for the days I need to travel. Besides, If I fly out of SJC, I have to factor in parking costs of around $10/day, whereas flying out of Oakland, I can take BART or the Capitol if it times correctly.
I need a few more United miles to put me over 120,000 (needed for a pair of business class upgrades on the expected trip to Japan next year for Lisa and me), so I priced United out of OAK. The good news was that it worked out around $50 less than Southwest. The bad news was that it required changing planes at LAX and the only possible flight at that fare left OAK at 6:40 AM. That means that to get to the airport by BART I need to be at Fremont BART at 4:15 AM to catch the first or second train of the morning. And that means that I can't take the AC Transit bus to BART because the first bus of the morning doesn't leave until 6:19 AM. Which means that I need to drive to the BART station, and since the days I'll be gone have three non-weekend, non-holiday weekdays in them, I'll need to pay $5/day for long-term parking. (And you don't get credit for the three weekend/holiday days embedded therein.)
I even considered flying only as far as LAX and then taking the train the rest of the way, just because I'd be arriving so early otherwise and because I'd like to ride it. But getting from LAX to LA Union Passenger Terminal involves riding a shuttle bus to the Green Line, then transferring to the Blue Line, then transferring to the Red Line. If I were traveling with just a briefcase and small bag, I might have considered it, even though it's more expensive overall; however, carrying a medium rolling bag and a computer in a backpack and a briefcase, I decided that it just wasn't worth it, train-brain or not.
Working through all of the permutations, it's about $20 less expensive total to drive to Fremont BART and park and ride BART to catch that 6:30 AM flight on United than it would be to fly Southwest and take the Capitol to connect to/from my flight. And I get the frequent-flyer mileage on United, whereas I've not been flying Southwest enough lately for it to do me any good. So I booked the United ticket. At least it shouldn't be difficult to find a parking space at BART at 4 AM.