According to the album "Elvis For Everyone" - Blue Hawaii" was the biggest selling Elvis album up to 1965.
I decided to have a read about the 1963 Great Train Robbery and I was amazed that the £2.6 million that was stolen is now the equivalent of £39 million in today's money. £2.6 - £39 million is about a15% increase, so I got to thinking about the $ million albums hat are listed on the back of the cover of the 1965 album "Elvis For Everyone." They don't really look very impressive anymore. There are 15 albums listed from 1956-64 each of them have their worldwide sales. Looking at the biggest seller at the time - "Blue Hawaii" with a total of $5,025,000, this album looks more impressive when brought up to today's value - $75,375,000. Even "Roustabout" which was released in 1964 had a nice healthy sale of $1,125,000 not bad for an album that had only been out for one year, but when brought up to date it works out to $16,875,000.
The total sales for all the albums listed (and it does not include "His Hand In Mine") comes to $30,350,000 and in today money that's $455,250,000 and this doesn't include all the singles and EP's that RCA released from 1955-65.