Driving would probably be the most inexpensive option. Thing is, it is the least relaxing, and parking in San Diego is a bitchass (although we might be able to park it at a friend's). Also, it's the most risky, since I'm not sure about how my car (we'd be taking my car, no other car is available) would be able to hold up.
It's a 1991 Honda Accord @ 177,000 miles, undergone no major repairs like engine replacement or anything, but it's never broken down, either... had its oil changed yesterday, its tires are fine, and overall, it's very reliable. So despite high mileage and old car, think it might be able to handle the drive back and forth?
Amtrak is slightly more expensive, at $112 round trip per person. Also, the schedule is not as flexible... there are only a few trips available each day, and they don't really fit us. But it would definitely be the most comfortable.
Flying is probably out of the question. It's the fastest, definitely, but it's really expensive... more than twice that of Amtrak. Probably ridiculous to reserve a flight down to San Diego around this time, anyway.
Any suggestions, ideas, responses, pandas, free refills?