Gris, a few years ago there was a sub-division in the DFW area that required all the houses to have cedar shingles. One house caught fire and the fire spread to several other houses. After that the rule was suspended. The fire department said that if all the houses hadn't had cedar shingles then the fire could have been contained at the original fire site. I don't know if they can be fireproofed or not. There are metal shingles out that look like cedar. I have no idea what they cost. When I was a Realtor, I never had a buyer reject a house because of the type of shingles it had. Also, regardless of what the roofer says, I've never seen a shingled roof that the shingles didn't eventually cup and curl. But in his defense, most of the owners didn't take the time to maintain them either. It's just my opinion but I wouldn't pay the difference for the cedar. One other thought, what does installing cedar shingles do to your insurance rates? Again, just my thoughts and not law.