Tests are taken almost every alternate week with a full test once in two months. The frequency of Tests increase as JEE/NEET Approaches and more All India Open Tests are conducted. They used to charge you about 10k for a year ( JEE Main+Advanced Test Package) in 2019. Of course that was for offline test series, in today's trend of Online Test Series, the rate must be lower around 5-7k. Allen also provides a very structured and weekwise segregated study plan and schedule for the tests as well as detailed analysis and solutions after test, besides the Result and Ranking on its DSAT Portal.