I spent a week in san fran in may and stayed at the adante hotel which is a 10 minute walk from union square. I went for cheapness as i was only in the hotel to sleep so wasnt expecting much. Its a small boutique style hotel and was adequate for the money, there was a complimentary breakfast of juice, coffee, muffins, toast that saved buying a breakfast every morning, for the money and the location it was worth it. Never felt threatened by the tramps, most tended to be at the union square end anyhow. On the same street theres lefty o douls where you can get a breakfast or choice of roast dinners all day at a very good price. Like anywhere SF is as expensive or as cheap as you want it to be. The 3 hour grey line bus tour around the city is well worth it as is the trip over to alcatraz, the bay tours are pleasant sailing under the golden gate bridge, fishermans wharf is a vibrant part of the city with much to do. The bus service is excellent and for $1.50 you could use your ticket for up to 4 hours allowing good travel options around the sights like lombard street(crooked street), and the golden gate bridge, you can also go by ferry to sausilito and take in the nappa valley tours if you want to. The city is split into districts like the haight, mission, twin peaks, etc and all have their own charachter. A great place and somewhere i would love to visit again spending longer. Oh and as a real ale fan there were plenty of brew pubs too
Would recommend SF to anyone.
