$50 can go a long way. Basic tools, lights, clothing, firemakers, water storage ....

A trip to the secondhand store can get you lots of perfectly usable stuff plus a donation to a worthwhile charity.

Maybe include a "coupon" to help them build inexpensive kits and develop solid plans?

But it occurs to me that if they're already interested, the best gift isn't necessarily "stuff," it's "information."

How about some good, motivating survival-related books?