This place is going to be your best value for your price range. It is a few blocks from Union Square. The location is a bit too "Tenderloin" for hiso types, but that explains the price. If you like live theater, check out the half price theater ticket booth at Union Square, similar to NYC but obviously smaller scene.

Yes I have toured this hotel and it very charming (though never stayed there).

http://www.hotelmarktwain.com/