The new Dual Layer disks are about $4 each from what I have seen. I think MacMall/PCMall had them for $60 for 15 recently. I have a burner capable of them, but, at $.50 for two disks versus $4 for the same storage, call me cheap, but, I'll use two DVDs
Office Depot does appear to be dumping the media at about the best prices I've seen recently, but, I haven't seen the Dual Layer DVDs there yet.