Hi Kerry,
San Francisco is known as one of the most expensive cities in the U.S. to live in. Buying a home is formidable. And residential apartment rents are very high. Short term rentals will have an even higher rent (broken down by week). So I doubt that you will be able to find an economical rental...especially somewhere near the centre. (Hopefully someone else can post a reply and prove me wrong.)
*´¨)
¸.·´¸.·*´¨) ¸.·*¨¨)
(¸. Michelle ¸.·´
(¸.·´ (¸.·* (¸.·*´¨)