Dna test is necessary for so many things but many people don't do it because of the dna test price. But now a days the price of dna tests dropped so much. A legal DNA paternity test (with court-admissible results) for child support, child visitation, and immigration, typically costs $300 to $500, and includes professional DNA collection. A non-invasive prenatal paternity test (testing before the baby is born) is $1,500 to $2,000.