We just had a new woodstove installed at our cottage (I know, very unmustachian, but not everyone wants to retire early). The doublewalled stove pipes were the most expensive part. We got a few quotes that varied a few hundred, but they were pretty much the same (in Ontario). We also took into consideration the WETT inspection. In ON woodstoves cannot be insured without a WETT inspection, which costs about 300$ (but is included in the installation cost). So, even if we busted our butts and did it ourselves, we would have to pay that amount for the inspection (plus mileage for the inspector)....