Le Cube has some interesting history behind it. This is an early '80s "knock-off" but what makes it different is that the company that made it, Dayton Hudson Corp. got slapped with a lawsuit by Ideal which had the licensing rights at that time. Georges made a good post about this in the past, I'll try to look for it and update this post.
Obviously, it's worth more if kept new and sealed. Value-wise, I would think that this would be worth $15-25 new. If opened, it won't be worth more than a few dollars.
Edit: Found it.