I don't know how kosher it is to post this link, so dear, kind, benevolent powers that be, if it ain't proper, please delete this and I'll learn my lesson.

Turner Classic Movies is having a sale and dropping some really good classic sci-fi movies by 50%. Some are as low as three dollars! Others are not that much on sale, but hey, it might be just enough off for you.

Here is the link to the sale page.