Stevia is a pain to start growing and that is why you should buy the shoots rather than seeds. Once it is going, you can dig it up and move it with you wherever you go. Easy, hardy, and yummy since a little goes a long way.

I use liquid stevia as a natural sweetener but was unaware that the plant will grow here in this climate. It came from somewhere in South America and is 200 times sweeter than refined sugar.

Stevia is a good idea, I'll have to go to our local farmer's market and see if anyone there sells cuttings or something.
Today I did a little more acquisition of stock for my homestead. I bought the start of a spice collection, a 1.5 pint size bottle of black pepper and 2 smaller bottles of paprika. There is an IGA store nearby that has much better pricing than many of the other big name stores on numerous items so I buy from them depending on what I want. The pepper was half of the other stores prices and the paprika was about 2/3 the price for the same size container.
Even thought they are well packed from the distributor, I decided I would also invest in several boxes of plastic freezer use sipper bags to store much of the food items. I take the small packages out of the boxes they are sold in and put them in freezer bags then squeeze out as much air as possible to seriously reduce the size of the package.
Being that the bags are thick walled, they offer a bit more protection to moisture, etc. than the cheap thin film bags. I'll use lots of them.
Thinking about it a bit more, any type of foodstuff will be used as a currency of sorts, especially for barter as some will have plenty of food and others will have plenty of something else and they will, hopefully, reach an accord for trade.

Invest in some stevia cuttings and plant them! You can take them with you. It can be the sweetener everyone wants. You can buy the seeds and I have but it takes a long time to grow them to the size for production so I keep my patch growing all the time. When sugar is gone...it is an excellent alternative.

I have never thought about bartering with spices but I have stockpiled about 4 bins of them. We have a grocery supplier here (like Watchman) that I have known for years and he will let me buy bulk items. I have purchased a lot of bulk spices from him although I did not do any special packing since they are factory sealed in their containers. I just pack them up as is.

Spices!

Remember your history lessons? Centuries ago spices were the gold of their day for their health, medical, food preservation, food preparation capabilities and anything else where spices could be used. Those little bits of vegetation were literally worth their weight in gold or more than their weight considering some of the wars and battles fought over spice trading routes as well as for spice production areas.
Part of my afterwards plans are to have copious quantities of various spices kept in reserve as a trade, barter or currency. I'll start with black pepper and once I can figure a good storage means I'll add to the collection from there. I'm figuring I'll keep the spices in mason jars that have had the air removed and replaced with nitrogen as I have copious quantities of nitrogen available for my use and a means to nitrogen pack items to reduce or eliminate spoilage. Remove the oxygen and whatever should not spoil, at least I'll find out with my first attempt with pepper.
If that works I'll add to the till and become a potentially wealthy man when the world falls apart. Or get myself killed because I have so much and others have nothing.
We'll see.

Still, like storing sugar and salt, storing a variety of spices to use as needed is a good idea and, if you can get an herb garden going you may be able to use it as a currency of sorts to obtain items you desire or need.

Thoughts anyone?