Salt, sugar and vinegar, in as large quantities as you can. Why? Because you cannot preserve food without these, and people are going to be into food preserving in a big way post PO.
Also over the counter medicines for bowel upsets, stings, any first aid stuff.
Matches. Lots of 'em.
Spices. How easy are spices to grow where you are? Remember how valuable spices were in medieval times - that's because they were difficult to get in Europe and nigh on impossible to grow there. Pepper, nutmeg, cinnamon, mustards etc. Sure, they're luxuries, but you probably don't realise how much of our food now incorporates them (so you're going to miss them when they're gone) and again, they're vital for preserving foods.
Coffee. Tea. Huge quantities. Again, how easy are they to grow where you are?
Organic seeds.
Seed potatoes. (an ongoing crop for you)