I'm a 2nd generation asphalt paving company so hopefully this help. Up here in CT we get from $2.75$3.00/sqft for a strip (remove old asphalt) and pave. That would include 2"4" of base installed and graded and a 2"2.5" asphalt mat AFTER compaction. Most material vendors have calculators to help with material but basically for asphalt itself take the square footage divided by 100 and multiply by 1.25 for a 2" after compaction job to calculate tonnage of asphalt. Lets say 1000sqft driveway  1000/100=100X1.25=12.5 tons for that job... The formula is the same for 2.5" just multiply by 1.56 to = 15.6 tons (basically 15.5 tons) but always round up to have a little extra on the truck to keep it hot. Never pave less than a 2" mat for driveways or single course paving... anything less will crack over time and ruin your reputation.
