Hey Giuseppe, we are from the same country and I’m almost done with the same thing, only finishing the website and adding the last necessary features.
Was planning to buy a new car before getting into this project. Had to invest all that money into it.
Dont want to put you down but it’s way harder than you can think before doing it. The first engineer I hired was sure to be able to do it, he failed and wasted one month of my time and of course some money.
Wasted so much money into testing the right hardware, when you solve something there is always something else you hadn’t think yet to do.
If you are doing it for yourself and you dont need a website too I guess you can get away with it with 6k for 100 proxies. Each dongle cost almost 30€ when bought in bulk and you have to find someone that can code and setup everything for you, surely 20/25€ per hour guys wont be able to do the job.
Regarding the usage per month I gave some test proxies to a guy that runs clients accounts. 10 accounts per proxy and he uses 70GB/MO more or less. He surely post, scrape and has all the tools on btw so you could maybe stay in the 50GB scraping externally and optimizing a little bit.