If you’ve ever canceled a range session because of rain, or watched your swing get rusty over a long winter, you’ve probably daydreamed about hitting balls in your own garage whenever you feel like it. That daydream used to cost as much as a used car. Not anymore. Launch monitor technology that was strictly for club fitters and PGA Tour trailers a decade ago now fits in a shoebox and connects to your phone. Radar units, camera systems, and simulator software have all gotten cheaper and smarter at the same time, which means a real, usable golf simulator is within reach whether you’ve got three grand or thirty. The catch is that most first-time builders spend their money in the wrong order. They buy a flashy launch monitor before measuring their ceiling, or they skimp on the mat and end up with sore elbows a month in. This guide walks…