HarperCollins and Zondervan (owned by HarperCollins) have drastically reduced prices on several Bibles. These seem to be publisher prices at the moment, so if you have a favorite seller other than the three I've linked, check there first.
The HarperCollins ebook of the New American Bible Revised Edition is $1.99. Note that this is a Catholic Bible and so includes the Apocrypha.
Barnes & Noble
Kobo
Amazon
The NIV is $4.99 (make sure you don't get just the New Testament, which is the same price!)
Barnes & Noble
Kobo
Amazon
The NIV Study Bible is $6.99 (there are several ebook editions, some still marked $19.99).
Barnes & Noble
Kobo
Amazon
There may be others.