Shoot film. It still cheaper unless you throw away most of your shots.
This is true if you are a weekend snapper. It's not true if you're doing a lot more than that.
Digital takes a lot more processing and storage on hardrives
Processing can be minimal if that's what you want. For most people, the digital printing labs do just fine with the processing. Storage is wildly cheap. Drives are going for about 75 cents a gigabyte if you shop carefully. For the average weekend snapper, that's storage for 500 images for 75 cents. For someone shooting RAW, it's at least 100 images for 75 cents. This is much cheaper than storing negatives or slides properly.
Photos: http://www.spirer.com
One People: http://www.onepeople.com/
Surfaces and Marks: http://www.withoutgrass.com
