Bruce, you, probably inadvertently and more or less innocently, spoke a phrase "self sufficiency" as something to strive for. That I think is really, really misleading. At the very best. But you mention "trade and barter", so I can see that you don't mean "self sufficient" to be a silo. And you mention a community in the nineties which seemed admirable to you, so you seem to believe in community. But the words we use repeatedly gather power and that "self sufficiency" phrase pushes buttons with me. So please forgive a small rant here.
To me "self sufficiency" is just a will'o' the wisp. A red herring. We humans live and create an ecosystem derived from our lives. Self sufficiency is as close to impossible for us as anything can ever be. Being part of an ecosystem is a huge part of being human. Size and degree matter, but the "self sufficiency" ideal seems mostly a distraction. Do you think that "It takes a village..." concept was wrong? I don't.
That means it's important to speak clearly regarding what is at the core, what matters and is a good goal. And not use words that can mislead, lead astray. "Self sufficiency" doesn't look to have good ramificatioins. It detracts, distracts and misleads from what really matters. In my opinion. It champions personal nationalism as a virtue, fosters us/them (even "me/them") and, most importantly, doesn't work for shit or even pencil out. And yet it appears over and over at the _center_ of talk and language about permiculture. That looks like a real problem because people glom onto and use popular phrases and then build on them. "Self sufficiency" does not look like a good strong rock-for-all-seasons to build your life on.
"Local", "responsible", "carry your load", "contributing", "community", "sustainable" "walk lightly", "waste not".... Fair, courteous, considerate, thoughtful, persistent,.. Well, I'll cease there because I wouldn't want anybody to think I"m a boy scout.
Those words and concepts and more like them seem _much_ healthier and challenging and sustaining than "self sufficient".
One of our members reported in as a hard core prepper dude and he described how he came around to thinking that "self sufficiency" was a quick road to disappointment and maybe disaster, if not oblivion. I'll try to find the thread and add the link here. Last I read, he's still a hard core prepper dude, but he's angling and arranging to foster a community rather than one silo. Seriously, and he didn't seem noob or wet behind the ears - not the first rodeo.
Words matter because _somebody_ will for sure take them at face value and use them. It could be for anything at all and the words will still carry their own values that will imbue the effort and be used by others to push it farther. Way better if the words we use actually hue to values that are good for us - and not values that will most like dead end.