I just purchased a Plextor DVD Burner for under $60 (49.99+9S&H).

The model is PX-712A.
* 12x4x16x DVD+RW
* 8x4x16x DVD-RW
* 48x24x48x CD-RW

DVD+R (and -R) have become a really affordable backup mediums (about 50 cents a pop). I briefly thought about getting a dual-layer DVD-burner but decided against it, because the media is still very expensive. I don't think that the price for these dual-layer media is justified considering the fact that one gets only double the space (about 8GB).

I think the future belongs to blue-ray DVDs, which will hold about 40-60GB of data.