Really? How much is the hotel? If it's $100/night, which I don't think gets you a very good hotel, and you stay 20 nights a month, that's already $2000.
But then again you can live in a fancy apartment downtown in the heart of things for around $1.2k a month.
Living outside the city isn't too bad, south of SF you can find 1 bedrooms for ~1200 if you don't mind a 30+ minute commute (traffic/train), or Oakland there's plenty of 1br/studios for ~1000, but you deal with higher crime and a social stigma that you live in Oakland.