Body and BMI Calculator. Your body mass index (BMI) is one way to estimate your body fat and see if you are at a healthy weight. The Fit Teen BMI Calculator computes your BMI and will tell you how your BMI compares to other kids.
In the top bar are tabs indicating the main features: Dashboard, Scan, Settings and History. At the end of this bar are two links urging users to create Malwarebytes user accounts and upgrade to the Premium version, which costs $24.95 per year.
Pretty cheap since I usually let them enjoy it. Other places charge per hour or per job (if they have job types such as hard drive replacement, malware removal). I usually don't charge people that much because it's more of a convenience to them, but between $20 and $30/hour depending on the job. The above should be like 2-3 hours tops with exception of #6.