From my experience:
If you don't care about embellishments then Blurb is the cheapest out there for lots of pages (I've done 200+ pages with them).
If you like the scrapbooker look then Mixbook has the most options for backgrounds and stickers but they only go up to 99pages per book.
Groupon used to have blurb coupons but they don't have any recently. Mixbook is still available on groupon regulary.
If you don't care about embellishments then Blurb is the cheapest out there for lots of pages (I've done 200+ pages with them).
If you like the scrapbooker look then Mixbook has the most options for backgrounds and stickers but they only go up to 99pages per book.
Groupon used to have blurb coupons but they don't have any recently. Mixbook is still available on groupon regulary.