After reading your question, I involuntarily scratched the back of my head 
Re-roofing yourself is, of course, possible, but is it optimal? This is a very time-consuming process and you will need someone to help you anyway. In my opinion, it is better to hire trusted roofers and delegate this task to them. By the way, what type of roof do you want to make? I read about the versatility of standing seam sheet metal roofing https://monarchyroofing.ca/standing-seam-metal-roofing/ . It seems to me that this is the most reliable option and the most durable. In terms of price, I don't know how much it might cost. You need to find out from specialists.
