hi!
I have experiences with python and also php, but I think python is better for this project. So i want to develop in python, if it is not problem for you.
I have no experiences in Slic3r, but if the output is a simple text file, or any file I think it's no problem.
I have a full time job as software developer, so I can work on it only in part time, that's why I need 3 days, but I think it's a easy task. I think one day can be enough too, but the quality of code is more important for me, than the length of development.
I fully understand the project from the desciption. The program should read all line of the file, and if E is start to decreasing or increasing should write additional lines in the output file.
The prize is lower than the average, because I need positiv feedback in this site to get more projects. If it is to much for you, please write me, and we will speak about it.
If I won, i will send you all my contacts (skype, facebook, phone number). So you can speak me every time when you want.
update:
I have checked your updates, thanks for more details, I understood more about project.