Letter to Hippie Camp

You'll see what I'm up to. I wrote:

Hi Patrick. I don't know if you remember me from 2003 summer workshop. I'm trying to make an acceptable foundation for a 10 x 10 square (must be square; will explain later if you like) cob structure in a very wet environment. When I computed the cost of a perimeter foundation it was in four digits of expense -- not doable for me. But when I figured the cost of four little pylons the cost came within reach -- about $200. It was suggested that I use wide steel spanners to span the pylons and support the heavy cob walls. But I don't even know how heavy cob walls are or how strong steel is supposed to be. What am I up against?