Material Costs. As of 2013, carpet costs range depending on the quality you desire, with a low-end carpet ranging from $2 to $3 on average per square foot.Carpet is actually sold by the yard, but most shops advertise in square feet to avoid customer confusion.aterial Costs. As of 2013, carpet costs range depending on the quality you desire, with a low-end carpet ranging from $2 to $3 on average per square foot.