Except the dates the OP is looking for are midweek. That said, these dates follow the Columbus Day weekend and that is almost always peak season for leaf peepers. In addition, many colleges have homecoming weekends around those dates and with the Head of the Charles the next weekend, rowers have to arrive early to rig their boats. I'm with Analise, try Priceline. Back Bay proper will be expensive. $130 a night will have you commuting in from the side of some highway in the 'burbs.