There is a difference between 20 and 30 shingles,
the major difference lies in the life of the proof.
A bundle of shingles is is a 10x10 ft amount of shingles and it called a square feet.
If you`re using asphalt shingles which generally cost $3 per square foot for material and installation.
The pricing would be different for new construction and for a re-roofing.
It also depends on the area or locality where you live as the local weather conditions can play a big role in determining the type and quality of roofing materials you will need.
The base price per sq foot can start at just $1.75 per sq.
if you have a 2000 sq ft roof,
and you put in a 20 year asphalt roof,
will labor you`re probably looking at paying about $4500 with labor.