My thoughts go along the line of buying more (in your case a lot more) of stuff you already need, use or eat. Think about things with a long shelf life.

Rather than just expendables, think about community systems. Maybe good rechargable batteries and a way to recharge them. A generator (gas diesel propane) or solar panels set up with a battery charging system could be handy for a group. If your house was set up with an off-grid system to keep food cold, you could save a lot of your neighbors food if you also had a freezer bigger than you require. $.02