My RS book on Turkey/Istanbul is not here yet. I have read that hoteliers in Turkey read their reviews and increase their prices. Is it possible to get a reasonably priced hotel in Istanbul and western Turkey without advance reservations from local TA offices? I am thinking of going in Sept/Oct or November on short notice. Right now I can't make long term future vacation plans for a while.
Have never used local TA offices in Turkey for hotels, but we found hotels all over Turkey on booking.com. It's great for last-minute bookings, as the website will just show you the hotels that have availability. Check the rules for each hotel carefully before you book; most hotels (but not all) can be cancelled up to a couple of days before arrival, with no fee. I always check Trip Advisor and the hotel's website before booking, too, for last-minute specials and other information. Sometimes you can save money by booking directly with the hotel, but again, carefully check for any deposit requirements or cancellation fees.
I also have not used Tourist Info offices to find rooms in Turkey. I have chosen rooms using either Rick Steves' or Lonely Planet guidebooks, or gone with a hotel tout/runner who met my bus arrival, or just by walking down the street in a small town. Many Istanbul hotels can be booked online or by phone whenever you're ready to book.