Nope. You don't trade anything. You will do EVERYTHING yourself - this is the explanation that some Brooklyn-bigwig gave me. Yes, my friend, be prepared to spend hard days producing your shingles from clay....naked, shoveling with your barehands! Once you have enough shingles, YOU and only YOU get up on that roof of your miserable little mansion and layout the shingles....there is no such thing as "John's Paradise Roofing"-company in "Jehobahs Yellow Pages - serving you since Armaggedon fried the old Telephone book". Nope. You will lay them quick and dirty, because rain is such a bitch on your living room carpet that took you 23 years to string together with fingernails and teeth - again: naked!
Then you will dedicate yourself to construct a god damn shovel....because, you know, you hate diggin your fingernails into the dirt. You will start ore mining and using your toenails you will scratch rock to get basic metal splinters and then you will create a fire and melt this shit and create your basic shovel (did I mention that you are still naked, because your lazy wife takes forever to string a thread that is long enough to clothe you and your children and besides that she is still working on the red yarn, which means you will all look like stupid shitheads).
Sounds like fun. Takes lot of millenia until you find out that your life is living HELL!!! HAHAHAHAHAHAHA.....(you will one day USE that shovel to kill Brother Thorn by beating him endlessly....I promise.)