Just because Zillow indicates a particular value does not mean that you could actually sell for that price. Zillow is using automation to come up with an estimate. Real buyers often feel differently about the value. The buyers for high end homes ($2M is atypical even for LA) are much fewer than for “regular” price ranges, and each home tends to be unique. As a result, these homes often sit on the market for a long time even during a boom waiting for a buyer who can afford the home and likes it. If you waited another six months and asked for the extra $600K, you might have still been sitting on the listing as prices turned down.

BTW, for those who didn’t look at the info, this home is in LA, not anywhere in San Diego county.