I have been looking at a lot of home/garage gym vids and the one thing that keeps coming up is that most of them are over equipped. Many are gyms owned by "collectors" who seem to think that more is better. 7-10 barbells? And all of them are crappy but they spend $3k on a leg press. Anyway, the point I make is that you probably need a lot less than you think. Many of them are trying to be a commercial gym with the space packed with machines. About 90% of the guys look like they don't lift.
Power racks are actually pretty crappy for squats, but you can make do. They can also be used for bench press but probably their most useful feature is that they provide a structure to use lots of other things, such as dip bars, cable row, pull-ups, landmine work, etc.
I am building my own gym next month and, gasp, it won't have a power rack. Nope. A lot of the stuff will be home made, most of the other stuff will be second hand but it will have a calibrated competition barbell and calibrated plates. You know, the important stuff (if you are competing, not so much if you are a bodybuilder or just a gym bro).
Have a think about what your goals are. That will dictate what you need, as opposed to what you want or what others have.