Unfortunately.......no. The taxi unions have politically blocked mass transit from accessing the airport. A cab to SD will cost about 30-35 USD. The only option, if you are traveling light, would be to either hoof it or take a cab just to the highway and flag down a guagua. This would get you into the city, but not to your hotel of course, but if your Spanish is good enough a friendly local could probably help get you on the right publico. I'd just pay the cab!