mine is going to be 8 course or so of brick then im going to make 4 panesl from 2x4 with nice overlap clading, once screwed together i dunno bout the roof, i like the pantile looking sheets or little biscuit tiles depending what i turn up
i like wood over brick

i wouldnt have a clue on cost, im buying a mixer at the weekend and build it myself unless it looks all wonkey