There is an Oracle convention the week after so a lot of people could be coming in early to visit the city. Last year rates during folsom were expensive if you could find a hotel. I think there was a convention either the week before or after, and Parc was sold out and so was the holiday inn at the civic center. I paid a lot to stay at the Hilton and ended up taking a red eye home sunday after folsom to save on an extra nights hotel due to the rates being so high. For people living in the east that is a great way to save on a hotel. Fair is over around 6 and that gives you plenty of time to grab something to eat, grab your bags at the hotel and take bart back to SFO.