I placed your project at 11 eur an hour, however this amount could go up or down at descression and more knowledge of what you really need.
I am very good at audio editing as i went to collage for it and excelled graduating top of my class, mostly in part to my work in the production lab.
I Edit all files, down and then provide the final in two forms, one a wav file as its base and then the MP3 file, were you to need any formats other then those i have listed its no problem and no additional charge for that or any copies needed in the future (due to loss of files, or other reasons)
I noted also you put up to 4 weeks of work. I am not sure if it will take 4 weeks or you have just like me over estimated time and money. I assure you, once on your project it becomes as valuable to me as it is to you, i dont' waste time however if you need me for 4 weeks or longer that is not an issue at all.