RHT, I think your question is actually somewhat reasonable. What we do and what you need to decide is how much does each PIECE take. For instance, we can generally wall mount a plasma in 4 hours (2 guys, 2 hours). Does it need additional wiring? Once again, we charge, $65 per wire drop, retro-fit multiply by 3. Just add up your starndard labor rates for each part plus trip charges and you'll have a pretty good estimate. We usually try to estimate worst case scenarios so we don't get stuck. The down side is that we do lose jobs to guys that say "well, I guess it should take about 24 man hours" without doing due diligence. Most of the time we catch these customers on the rebound anyhow.