It more likely has to do with the fact a disk costs $2.50 to produce, the studio sells in it different countries based on what the market is willing to pay in that country.  The same disc could sell in Europe for $69, North America for $49, Asia for $29 and South America for $9.  It's easy for me to send $50 to a friend in Bolivia who buys 4 different titles and then mails the discs to me, in North America giving me $196 worth of movies for $50 and reducing the studios profit by $146 and we couldn't have that.