There have been a whole load of national news items about this subject just in the last week or so - Which mag highlighted it.
The methodology is to delete cookies when you have a range of prices - then go back and see what they quote ... or better still if you have two devices to use at the same time look at the deals on one and then book on the other.
I discovered this years ago when booking with Travelodge - find one room and book at price X - go to book a second room on the same date at the same place and price will be X+ - delete cookies, close browser and start again with a fresh booking and hey presto you get the original price X. The same concept applies to loads of sites - and especially the charming Mr O`Leary`s airline .... do the research, delete the cookies and make the booking.
Have to say I have almost always found that booking direct with the property is better than booking.com, hotels.com, expedia.com or any of the other sites - see what the price range is and go direct. Lots of hotels guarantee to offer rates below the so-called best price sites.
Best Western isn`t a hotel chain but a marketing group (as is Holiday Inn) so again direct to the property is often better than the central booking system (ditto Logis de France and may other groups)
.. and don`t get me started on insurance products with exactly the same cookie scenario
Rob