No.
Remember, you're not paying $50 to purchase your own copy of the 4-disc print. You're donating $50 towards funding a very large print run.
Think of it this way: you're not paying for one copy. You're paying for a bunch of copies, and we toss one of them your way as a thanks.
When all is said and done and we've sent out all of the backers' rewards, we still need to have copies of the album left over for promotional stuff.
Kickstarter isn't a store, and people shouldn't think of backer rewards as purchases, even in the not-for-profit way. The situations are not really the same at all.