Android - Assistance with In App Billing Library - $40 Dollars

Hi. I have been developing an App for months, new to Java and "Programming" in general. Now, I am getting close to the last days of development of the App. So. I want to start implementing the In App Purchases/Subscription System. . I have seen a couple of Libraries for doing this. Like this 3: [login to view URL] [login to view URL] [login to view URL] . Yet, I am seeing that I need help to develop this in a short time. So. Anyone who has already implemented this type of implementation, using any of these 3 libraries, or not, just believing that can help me do it in a short, and efficient time, can send me a message. . I have a budget of $40 Dollars for this task. . Yet, perhaps, I will not require more than 2 Net Hours of your Assistance. . So. This is all for the moment. . Thank you for your time. .