Have to agree with that, but have you seen where we can go ?
http://opensourceecology.org/
With 3D printing, especially Direct Laser Sintering, and maybe a 5 axis CNC lathe, can make most of your mechanical parts.
http://www.disn.co.jp/gallery.html
If you could figure out a home built plastic recycling system with powders for a RepRap, and simple sheet maker for sheeting and windows, you would be even closer.
How much electronics do you really want/need in a low tech environment ?
Even meds are possible - with fungi.
http://www.eurekalert.org/pub_releases/2007-06/ps-mmm062207.php
Just saying, there are still ways to produce surpluses for trade and to help keep a village going.
Got another group working on asteroid mining, and know exactlly how dependent people have to be, but working from that end, and figuring out how to make plastic, parts, air, and fuel, let alone food, is just as amusing.
