I've yet to hear of anyone who made a million selling nettles Mind you the Arabs import sand and some people here prefer to go out with an umbrella to Tesco's and buy their water fresh from the French Alps (or is it). So don't rule anything out . Colud be quite a seller in the far east (just for the record this message is recorded should you nick my idea)
Another great food is hemp seeds, they can be made into a porridge too, called gruel. Hemps seads are the mpost nutricous single food source available. So no wonder Oliver Twist asked for more gruel.