You can get a good many manuals on cd for under $10 including shipping. Your best bet is actually Ebay as these vendors compete with each other and have no overhead.
I got 3 of the Ranger Rick manuals and was a little disappointed. The first three at least are geared for the military with how to pass inspections and make alterations to your equipment (with survival and loading bearing emphasis). Some of the suggestions on what and how to carry stuff are good but primarily in a modern situation.