re: Cedar vs. Treated Pine Privacy Fence

IMO.... $6000 is a little high, $5000-5500 is what I think it should cost. But, it does depend on access to the yard. If it is difficult to access, this drives up the cost.

Just putting up the new fence should be about $4500 [$26/foot] then add the cost to haul off the old fence. Add about $500 if you need a gate.
The price can vary some depending on your location. There may be a "Handman" in your area that can do this work a little cheaper. Get recommendations.