Nicci, thank you very much.
I called and successfully booked. Here are the details for everyone's benefit:
AS award, SAN-SJD RT, 802 miles, coach, nonstop flight
If booked on AS:
35K miles RT, $77 fees
If booked on BA:
15K miles RT, $110 fees, $25 phone booking fee
Using BA avios saves 20K miles and costs $58 more per ticket.
I don't know these fees on AS, but was given these fees for Avios.
$65 to cancel or change dates on phone
$40 to cancel or change dates online
All in all, this is a sweet spot for Avios as long as I am firmly committed to my dates.