Hello, I think the project u're talking about is related to MLM. Its very difficult to estimate a time needed for the project before i know what it is. Ideally studying an existing project takes up upto 2 hours time. And then modifications, i am not 100% sure whether it can exactly be done in 2.5 hours (my min. hourly rate is 8$ for Indian Clients, you may check my profile for my reputation on freelancer), what i can do is use the Time Tracker provided by Freelancer which will capture my screen when i am working, using which u will know what i was doing on your project or whether i was actually working on it. Its the safest way to guarantee that i was working only on your project. Let me know what u think. Thanks