it's not even going to matter
like, really, a 32 GB micro sd card costs 10, so im assuming its like 3 production costs max.
a blu ray you can write stuff on starts at 15, so its probably more expensive to make, and can only hold like 20 GB max. the only reason discs are still in use is because blu ray and dvd players are still widely distributed. you can already see that the trend is shifting away from discs seeing as my (and other current gen) laptop does not even have a disc tray, however it does have a sd card slot.
also when we're looking at games, many current games either
-require a hueg download first time after inserting the disc
-come on like, 5 discs
or are just a steam key on a disc, which is because games nowadays greatly exceed (Final Fantasy 13 at 50 GB, GTA V at 60 GB) the max. storage a single blu ray can have.