This is an interesting exercise! This is the my first digital year and overall I think I spent less with a grand total of $641.72 on 303 books with the most going to :
Kobo - $209 (major hoarding with 50% off & $2 codes
)
Fictionwise - $163 (more hoarding with frequent 55-60% off codes)
Amazon - $110
I've also accumulated another 500+ freebies.
Pre-digital I would have purchased 6-8 new Big 6 paperbacks/month and spent $503 and probably spent that much again on used paperbacks. Right now there are 55 agency books sitting on my wishlist that I absolutely will not buy in any format until the Big 6 get a clue.
I purchased exactly 1 fully priced agency book when I first fired up my nook and haven't gotten any others unless they were on special. I will only spend up to $4.99 on an agency book if it is on my wish list and that has only happened once.
I've converted a handful of keeper DTBs to EPUB but never for more than $0.99.
Along the way I've discovered a number of new authors and branched out into some new genres. Letting go of favorite agency authors hasn't been very painful because at any time I've got dozens of books I'm dying to get to.