A typical 5-gallon bucket of asphalt sealant is sufficient to cover around 400 square feet of asphalt. Five-gallon buckets of cheaper sealants are available for as low as $5 in 2010. Higher-end sealants are available for upwards of $30 per bucket.
The cost of professional driveway seal coating can vary dramatically by region of the country. Professionally sealing a 1,000-square-foot driveway in the eastern United States can cost between $100 and $160 as of October 2010. Having professionals seal the same amount of driveway in the upper Midwest can cost between $85 and $100.
Seal coatings help prevent an asphalt driveway from rapidly deteriorating. Asphalt is very elastic, but if a regular seal coating schedule is not maintained, the asphalt will become brittle, making it prone to cracking. The seal coating helps the material maintain its elastic properties throughout the years.