UPDATE: This has now been fixed sadly. Still not sure if it was a glitch or an error on Capcom's part, but the discount is no longer being added to any orders.
As I was browsing through Facebook a few minutes ago, I came across a post on the Mega Man Unlimited page that said that for some reason, all orders over at the Capcom Store site were getting discounted by fifty dollars excluding shipping. The reason he posted that was because you can basically get thirteen Mega Man soundtracks for free, all you have to do is add five at a time and your sub-total ends up at zero due to the discount and lack of shipping because...well, you really can't ship out a digital soundtrack.
The soundtracks this works for are Mega Man X1 - X4, Mega Man 1-8, and Mega Man 10 (strangely they only offer the physical CD for Mega Man 9, but that'll still get discounted to nothing and you only have to pay the shipping). This is still working as of 2/6/2016 at 5:50 p.m. EST, and there's no idea of when it'll end/get fixed/whatever, so if you need some classic Mega Man music for your collection, now's the time to grab it.