You don;t need to. As long as your equipment is at least food-grade plastic, you can brew excellent beer. If your technique and recipe and sanitation are all good then upgrading to state of the art, fully automated, jet-propelled kit won't make it any better. So if you've got some kind of insulated mash tun- say a decent picnic box with a tap and manifold, a stainless steel boiler of some kind and a couple of food grade plastic fermenters, a reliable thermometer and hydrometer and a paddle or spoon, you've got enough. If you do BiaB, you can get away with even less.I'm a new brewer - I have already spent modest outlay on kit and don't want to invest in hundreds, if not thousands, of pounds worth of bigger, better, faster, shinier toys.
Of course there's nothing wrong with spending more, when you can, but it's not absolutely essential. I see some of the stuff people are using and think wow, that looks lovely, and then I realise that I could go to the pub and drink many hundreds of pints to spend the amount that has been laid out. But each to his own. If I had the dosh, I wouldn't buy a flash car either, but I would build a purpose-built, self contained outhouse to do my brewing in.