A perk test is also known as a percolation test. This is a soil test done to show how well soil absorbs liquid. This determines the number of bathrooms that can be built on a property as well as the size of home as far as number of bedrooms. The cost of these percolation tests will vary by location across the United States. They may range from $100 to $1,000 depending on the size of the property and the conditions of the site. An estimate can be obtained from a qualified tester before proceeding.