Just like the price of lenses, viewfinders are on a steady increase. I've recorded data from 2006 until now and compiled it into this neat and mostly-organized spreadsheet.
All of the information has been taken from Stephen Gandy's website: cameraquest.com (albeit different versions).
How to read the data:
- numbers highlighted in pink means the price has risen since its last recording
- numbers highlighted in green means the price has decreased since its last recording
- data from October 2009 was unavailable and so it was not included
- this is not a complete list of viewfinders (eg the 15-35mm zoom multifinder is absent)