The games are cheap and $30 isn't a huge amount in the grand scheme of things...
I own multiple games digitally and on disc such as Alan Wake, Gears quadrilogy etc so I wouldn't have said so. Particularly as discs are useless with BC except for checking you own the game. You might as well get them digitally if they are cheap and want to do it.
What are you buying?
If we want to count Steam & PSN... I'm a horrible offender of double and triple dipping
Looks like I may be grabbing Bioshock, Bioshock 2, Fallout New Vegas, Mass Effect, Prince of Persia, and Borderlands
Of those I haven't played PoP & haven't finished New Vegas (although being ass-deep in FO4 is making me want to go back to it afterwards). Everything else beaten, just not 100%ed