Sorry I only watched up to cube zero (was showing on the videos thumbnail ). I have all 3 cube movies as well and love them. To me the first was the best, but I like them all.
Cube zero was good cause it let you know how the savant gets in the group.
Edit: sorry I didn't answer the actual question. I think you got a good deal. You could sell the ones you don't want for a buck each at a yard sale and if you sell 50 then you got your money back.