We had it for the first few years of owning our current house – it was $127/year. We dropped it after my husband (architect) went through and did a “seismic retrofit”. He basically improved the diagonal bracing, stiffened certain walls so they’d act as sheer walls, and added additional bolts and strapping from the sill to the foundation. He said we’ll withstand a decent earthquake now… and if it’s bigger than what the house will take, we have different problems.
Depending on where you are in San Diego – you *could* have a major fault near you. We’re close to the rose canyon fault… so it was a concern for us.
The work my husband did is overkill – but the standards are so much more rigorous now, compared to when the house was built in 63 or 64.
If your house was built in the past decade or so – you probably don’t need any retrofit.