i live brushed up against the tenderloin about 4 blocks from union square. all the hotels directly around me are all pretty much 1000 year old cesspools of nastiness. if you go a few blocks down you will see like the pan pacific, or the 4 seasons. of course that would probably be like 5-10 times more than what you wanted to spend depending on the room. there are good deals. look online. when i decided to move out here to san francisco from indiana, i came otu first for a few days to find a place to live. i went on priceline and i got a suite at the hyatt at the airport for $50 a night, so thats something to consider. it could have been blind luck, but give it a shot