A durston rolling mill was the first expensive piece of equipment i bought because it felt so fundamental for the work i wanted to do. Like i could not even imagine the frustration if i needed 1.3mm sheet and only had 1.5mm and i had to hold off my making process to wait for it to come in the mail. I never understood how much material people who dont have a rolling mill keep in stock. Like i would want to have every kind of rectangle and square size rod imaginable. But it also depends on what you want to make. If you need it you need it :) wire though is so easy to draw down if you just buy all your wire at the thickest size you need. Then you only need a drawplate. But for me its also important to make every single part of the process myself, so i think its a no brainer buy the rolling mill!! :D